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{{Short description|Large permanent human settlement}}
{{Other uses}}
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| image1            = Palace of Westminster from the dome on Methodist Central Hall (cropped).jpg
| alt1              = London skyline with Palace of Westminster in midground
| image2            = Tokyo Shibuya Scramble Crossing 2018-10-09.jpg
| alt2              = People cross busy Shibuya intersection lined with electronic billboards at dusk
| image3            = Camille Pissarro - Boulevard Montmartre, Spring - Google Art Project.jpg
| alt3              = Impressionist painting of wide tree-lined Boulevard Montmartre with horse-drawn carts in the 1890s
| image4            = 1 rocinha night 2014 panorama (vertical cropped).jpg
| alt4              = Informal settlements built into the hillside in Rocinha, Rio de Janeiro, Brazil at dusk
| image5            = Fast-Paced Streets of New York City.jpg
| alt5              = Skyscrapers line a busy sidewalk along 6th Avenue in New York City
| image6            = 20191205 Targ przypraw w Starym Delhi 0703 6755 (cropped).jpg
| alt6              = Vendors and signs along a busy dirt street in Old Delhi
| image7            = Hong Kong Harbour Night 2019-06-11.jpg
| alt7              = Hong Kong skyline
| image8            = Metro de São Paulo, Luz Station, Brazil (square cropped).jpg
| alt8              = An underground train in the São Paulo Metro
| footer            = <!-- CAUTION: The images in the collage have been deliberately selected for geographic, visual, and aspectual balance. DO NOT make changes unless there is talk page consensus to do so. -->From top, left to right: [[Westminster Palace]] in London; [[Shibuya Crossing]] in Tokyo; [[Le Boulevard de Montmartre, Matinée de Printemps|painting of Boulevard Montmartre]] in Paris by [[Camille Pissarro]]; the [[Rocinha]] [[favela]] in Rio de Janeiro; [[6th Avenue (Manhattan)|6th Avenue in Manhattan]]; spice market in [[Old Delhi]]; [[Hong Kong]]; and the [[São Paulo Metro]]
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A '''city''' is a [[human settlement]] of a substantial size. The term "city" has different meanings around the world and in some places the settlement can be very small. Even where the term is limited to larger settlements, there is no universally agreed definition of the lower boundary for their size.<ref name= Goodall>{{cite book|last=Goodall|first=B. |year=1987 |title=The Penguin Dictionary of Human Geography |location=London |publisher=Penguin}}</ref><ref>{{cite book|editor-last1=Kuper|editor-first1=A. |editor-last2=Kuper|editor-first2=J. |year=1996|title=The Social Science Encyclopedia|edition=2nd |location=London |publisher=Routledge}}</ref> In a narrower sense, a city can be defined as a permanent and [[Urban density|densely]] populated place with administratively defined boundaries whose members work primarily on non-agricultural tasks.<ref>{{Cite book|title=Encyclopedia of the City|last=Caves|first=R. W.|publisher=Routledge|year=2004|page=99}}</ref> Cities generally have extensive systems for [[housing]], [[transport]]ation, [[sanitation]], [[Public utilities|utilities]], [[land use]], [[Manufacturing|production of goods]], and [[communication]]. Their density facilitates interaction between people, [[government organisations|government organizations]], and [[business]]es, sometimes benefiting different parties in the process, such as improving the efficiency of goods and service distribution.

Historically, city dwellers have been a small proportion of humanity overall, but following two centuries of unprecedented and rapid [[urbanization]], more than half of the [[world population]] now lives in cities, which has had profound consequences for [[sustainability|global sustainability]].<ref>{{Cite journal|url= https://ourworldindata.org/urbanization|title= Urbanization|journal= Our World in Data|date= 13 June 2018|access-date= 14 February 2021|last1= Ritchie|first1= Hannah|author1-link= Hannah Ritchie |last2= Roser|first2= Max|author2-link= Max Roser |archive-date= 29 October 2020|archive-url= https://web.archive.org/web/20201029185610/https://ourworldindata.org/urbanization|url-status= live}}</ref><ref>{{Cite book|last1=James|first1=Paul|url=https://www.academia.edu/9294719|title=Urban Sustainability in Theory and Practice: Circles of Sustainability|last2=with Magee|first2=Liam|last3=Scerri|first3=Andy|last4=Steger|first4=Manfred B.|publisher=Routledge|year=2015|location=London|isbn=978-1-315-76574-7|author-link=Paul James (academic)|access-date=20 December 2017|archive-date=1 March 2020|archive-url=https://web.archive.org/web/20200301210732/https://www.academia.edu/9294719|url-status=live}}</ref> Present-day cities usually form the core of larger [[metropolitan area]]s and [[urban area]]s—creating numerous [[Commuting|commuters]] traveling toward [[city centre]]s for employment, entertainment, and education. However, in a world of intensifying [[globalization]], all cities are to varying degrees also connected globally beyond these regions. This increased influence means that cities also have significant influences on [[global issues]], such as [[sustainable development]], [[Climate change and cities|climate change]], and [[global health]]. Because of these major influences on global issues, the international community has prioritized investment in [[Sustainable city|sustainable cities]] through [[Sustainable Development Goal 11]]. Due to the efficiency of transportation and the smaller [[land consumption]], [[Urban density|dense]] cities hold the potential to have a smaller [[ecological footprint]] per inhabitant than more sparsely populated areas.<ref>{{Cite web|date=18 September 2019|title=Cities: a 'cause of and solution to' climate change|url=https://news.un.org/en/story/2019/09/1046662|access-date=20 March 2021|publisher=UN News|archive-date=4 March 2021|archive-url=https://web.archive.org/web/20210304125023/https://news.un.org/en/story/2019/09/1046662|url-status=live}}</ref> Therefore, [[Compact city|compact cities]] are often referred to as a crucial element in fighting climate change.<ref>{{Cite web|date=30 June 2011|title=Sustainable cities must be compact and high-density|url=https://www.theguardian.com/environment/georgemonbiot/2011/jun/30/sustainable-cities-urban-planning|access-date=20 March 2021|website=The Guardian|archive-date=9 March 2021|archive-url=https://web.archive.org/web/20210309124623/https://www.theguardian.com/environment/georgemonbiot/2011/jun/30/sustainable-cities-urban-planning|url-status=live}}</ref> However, this concentration can also have some significant harmful effects, such as forming [[urban heat island]]s, concentrating [[pollution]], and stressing water supplies and other resources.

== Meaning ==
===Urban settlements===
Common population definitions for an ''urban area'' (city ''or'' town) range between 1,500 and 50,000 people, with most [[U.S.]] states using a minimum between 1,500 and 5,000 inhabitants.<ref>"[https://unstats.un.org/unsd/demographic/products/dyb/dyb2015/notes/notes06.pdf Table 6] {{Webarchive|url=https://web.archive.org/web/20170811011352/https://unstats.un.org/unsd/demographic/products/dyb/dyb2015/notes/notes06.pdf |date=11 August 2017 }}" in [[United Nations Demographic Yearbook]] ([https://unstats.un.org/unsd/demographic/products/dyb/dyb2015.htm 2015] {{Webarchive|url=https://web.archive.org/web/20180708191849/https://unstats.un.org/unsd/demographic/products/dyb/dyb2015.htm |date=8 July 2018 }}), the 1988 version of which is quoted in Carter (1995), pp. 10–12.</ref><ref name= Hugo>Hugo, Graeme; Champion, Anthony; Lattes, Alfredo. "[https://www.jstor.org/stable/3115228 Toward a New Conceptualization of Settlements for Demography] {{Webarchive|url=https://web.archive.org/web/20200729082041/https://www.jstor.org/stable/3115228 |date=29 July 2020 }}", ''Population and Development Review'' 29(2), June 2003.</ref> Some jurisdictions set no such criteria.<ref>{{cite web|url= http://www.nclm.org/resource-center/Pages/How-Municipalities-Work.aspx|title= How NC Municipalities Work – North Carolina League of Municipalities|website= nclm.org|archive-url= https://web.archive.org/web/20100516211303/http://www.nclm.org/resource-center/Pages/How-Municipalities-Work.aspx|archive-date= 16 May 2010}}</ref>

National [[census]]es use a variety of definitions – invoking factors such as [[population]], [[population density]], number of [[dwelling]]s, economic function, and [[infrastructure]] – to classify populations as urban.<ref name= reg>{{Cite web|url= http://data.oecd.org/popregion/urban-population-by-city-size.htm|title= Population by region – Urban population by city size – OECD Data|website= theOECD|access-date= 3 June 2019|archive-date= 3 June 2019|archive-url= https://web.archive.org/web/20190603220158/https://data.oecd.org/popregion/urban-population-by-city-size.htm|url-status= live}}</ref>

===City===
[[File:Sheth Motisha Tonk 01.jpg|thumb|[[Palitana]] is a religiously significant city in Gujarat, India.<ref>Moholy-Nagy (1968), p. 45.</ref>]]

A ''city'' can be distinguished from other human settlements by its relatively great size, but also by its functions and its [[city status|special symbolic status]], which may be conferred by a central authority. The term can also refer either to the physical streets and buildings of the city or to the collection of people who dwell there and can be used in a general sense to mean [[Urban area|urban]] rather than [[rural territory]].<ref name= OED/><ref name= KAL>Lynch, Kevin A., "What Is the Form of a City, and How Is It Made?"; in Marzluff et al. (2008), p. 678. "The city may be looked on as a story, a pattern of relations between human groups, a production and distribution space, a field of physical force, a set of linked decisions, or an arena of conflict. Values are embedded in these metaphors: historic continuity, stable equilibrium, productive efficiency, capable decision and management, maximum interaction, or the progress of political struggle. Certain actors become the decisive elements of transformation in each view: political leaders, families and ethnic groups, major investors, the technicians of transport, the decision elite, the revolutionary classes."</ref>

According to the "functional definition", a city is not distinguished by size alone, but also by the role it plays within a larger political context. Cities serve as administrative, commercial, religious, and cultural hubs for their larger surrounding areas.<ref name= Smith>Smith, "[http://www.public.asu.edu/~mesmith9/1-CompleteSet/MES-02-EarlyCities.pdf Earliest Cities] {{Webarchive|url=https://web.archive.org/web/20100629224053/http://www.public.asu.edu/~mesmith9/1-CompleteSet/MES-02-EarlyCities.pdf |date=29 June 2010 }}", in Gmelch & Zenner (2002).</ref><ref>Marshall (1989), pp. 14–15.</ref> The presence of a literate elite is often associated with cities because of the cultural diversities present in a city.<ref>Prokopovych, M. (13 May 2015). Literary and artistic metropolises. EGO. Retrieved 5 March 2023, from http://ieg-ego.eu/en/threads/crossroads/courts-and-cities/markian-prokopovych-rosemary-h-sweet-literary-and-artistic-metropolises</ref><ref>Kaplan et al. (2004), pp. 23–24.</ref> A typical city has professional [[Public administration|administrators]], regulations, and some form of [[taxation]] (food and other necessities or means to trade for them) to support the [[Civil service|government workers]]. (This arrangement contrasts with the more typically [[egalitarianism |horizontal]] relationships in a [[tribe]] or [[village]] accomplishing common goals through informal agreements between neighbors, or the [[leadership]] of a chief.) The governments may be based on heredity, religion, military power, work systems such as canal-building, food distribution, land-ownership, agriculture, commerce, manufacturing, finance, or a combination of these. Societies that live in cities are often called [[civilization]]s.

====Population size, density====
The ''degree of urbanization'' is a modern metric to help define what comprises a city: "a population of at least 50,000 inhabitants in contiguous dense grid cells (>1,500 inhabitants per square kilometer)".<ref>{{cite web|url=https://blogs.worldbank.org/sustainablecities/how-do-we-define-cities-towns-and-rural-areas|title=How do we define cities, towns, and rural areas?|date=10 March 2020|first1=Lewis |last1=Dijkstra|first2=Ellen |last2=Hamilton|first3=Somik |last3=Lall|first4=Sameh |last4=Wahba|access-date=2 October 2021|archive-date=6 October 2021|archive-url=https://web.archive.org/web/20211006193626/https://blogs.worldbank.org/sustainablecities/how-do-we-define-cities-towns-and-rural-areas|url-status=live}}</ref> This metric was "devised over years by the [[European Commission]], [[OECD]], [[World Bank]] and others, and endorsed in March [2021] by the [[United Nations]] ... largely for the purpose of international statistical comparison".<ref>{{cite news|title=What makes a city a city? It's a little complicated|first=Oliver|last=Moore|date=2 October 2021|newspaper=[[The Globe and Mail]]|page=A11}}</ref> Typical working definitions for small-city populations start at around 100,000 people.<ref name= reg/>

====In specific countries====
[[List of cities in Australia|In Australia]], the definition of what constitutes a city varies between the states.{{Citation needed|date=September 2025}}

In the [[city status in the United Kingdom|United Kingdom, city status]] is awarded by the Crown and then remains permanent, with only two exceptions to this rule due to policy changes. A lack of official qualifying criteria results in some particularly small cities, notably [[St Davids]] with a population of 1,751 {{as of|2021|lc=on}}.

== Etymology ==

The word ''city'' comes from the {{Langx|fro|cité}}, itself from the {{Langx|la|civitas}}, meaning "citizenship" or "state".<ref>{{Cite web |date=2025-11-10 |title=CITY definition and meaning {{!}} Collins English Dictionary |url=https://www.collinsdictionary.com/dictionary/english/city |access-date=2025-11-16 |website=www.collinsdictionary.com |language=en}}</ref><ref>{{Cite web |title=city {{!}} meaning of city in Longman Dictionary of Contemporary English {{!}} LDOCE |url=https://www.ldoceonline.com/dictionary/city |archive-url=http://web.archive.org/web/20231030200517/https://www.ldoceonline.com/dictionary/city |archive-date=2023-10-30 |access-date=2025-11-16 |website=www.ldoceonline.com |language=en}}</ref> The related (maybe) ''[[civilization]]'' come from the [[Latin]] root {{lang|la|[[wikt:civitas|civitas]]}}, originally meaning 'citizenship' or 'community member' and eventually coming to correspond with {{lang|la|[[wikt:urbs|urbs]]}}, meaning 'city' in a more physical sense.<ref name= OED>"city, n.", ''Oxford English Dictionary'', June 2014.</ref> The Roman ''civitas'' was closely linked with the Greek {{lang|el-latn|[[polis]]}}—another common root appearing in English words such as ''[[metropolis]]''.<ref>{{cite journal | last=Jianping | first=Yi | title="Civilization" and "State": An Etymological Perspective | journal=Social Sciences in China | volume=33 | issue=2 | date=2012 | issn=0252-9203 | doi=10.1080/02529203.2012.677292 | pages=181–197}}</ref>

In [[toponymic]] terminology, names of individual cities and towns are called ''astionyms'' (from [[Ancient Greek]] {{lang|grc-Grek|ἄστυ|italic=no}} 'city or town' and {{lang|grc-Grek|ὄνομα|italic=no}} 'name').{{sfn|Room|1996|p=13}}

==Geography==
[[Urban geography]] deals both with cities in their larger context and with their internal structure.<ref>Carter (1995), pp. 5–7. "[...] the two main themes of study introduced at the outset: the town as a distributed feature and the town as a feature with internal structure, or in other words, the town in area and the town as area."</ref> Cities are estimated to cover about 3% of the land surface of the Earth.<ref>Bataille, L., "From passive to energy generating assets", [https://issuu.com/energyinbuildingsindustry/docs/eibi_october_2021 ''Energy in Buildings & Industry'', October 2021] {{Webarchive|url=https://web.archive.org/web/20220212003528/https://issuu.com/energyinbuildingsindustry/docs/eibi_october_2021 |date=12 February 2022 }}, p. 34. Retrieved 12 February 2022</ref>

=== Site ===
[[File:Allegheny Monongahela Ohio.jpg|thumb|[[Downtown Pittsburgh]] at the [[confluence]] of the [[Monongahela River|Monongahela]] and [[Allegheny River|Allegheny]] rivers, which flow into the [[Ohio River]]]]
Town siting has varied through history according to natural, technological, economic, and military contexts. Access to water has long been a major factor in city placement and growth, and despite exceptions enabled by the advent of [[rail transport]] in the nineteenth century, through the present most of the world's urban population lives near the coast or on a river.<ref>Marshall (1989), pp. 11–14.</ref>

Urban areas as a rule cannot [[Subsistence agriculture|produce their own food]] and therefore must develop some [[city region|relationship]] with a [[hinterland]] that sustains them.<ref name= Kaplan155>Kaplan et al. (2004), pp. 155–156.</ref> Only in special cases such as [[mining town]]s which play a vital role in long-distance trade, are cities disconnected from the countryside which feeds them.<ref name= Marshall>Marshall (1989), p. 15. "The mutual interdependence of town and country has one consequence so obvious that it is easily overlooked: at the global scale, cities are generally confined to areas capable of supporting a permanent agricultural population. Moreover, within any area possessing a broadly uniform level of agricultural productivity, there is a rough but definite association between the density of the rural population and the average spacing of cities above any chosen minimum size."</ref> Thus, centrality within a productive region influences siting, as economic forces would, in theory, favor the creation of marketplaces in optimal mutually reachable locations.<ref name= Latham/>

=== Center ===
{{Main|City centre}}

[[File:Helsinginkeskustailmakuva 04.JPG|thumb|[[Kluuvi]], a city centre in [[Helsinki]], Finland]]

The vast majority of cities have a central area containing buildings with special economic, political, and religious significance. Archaeologists refer to this area by the Greek term [[temenos]] or if fortified as a [[citadel]].<ref>Kaplan et al. (2004), pp. 34–35. "In the center of the city, an elite compound or temenos was situated. Study of the very earliest cities show this compound to be largely composed of a temple and supporting structures. The temple rose some 40 feet above the ground and would have presented a formidable profile to those far away. The temple contained the priestly class, scribes, and record keepers, as well as granaries, schools, crafts—almost all non-agricultural aspects of society."</ref> These spaces historically reflect and amplify the city's centrality and importance to its wider [[city region|sphere of influence]].<ref name= Latham>{{harvnb| Latham | McCormack | McNamara | McNeill | 2009 | p=18 }}: "From the simplest forms of exchange, when peasant farmers literally brought their produce from the fields into the densest point of interaction—giving us market towns—the significance of central places to surrounding territories began to be asserted. As cities grew in complexity, the major civic institutions, from seats of government to religious buildings, would also come to dominate these points of convergence. Large central squares or open spaces reflected the importance of collective gatherings in city life, such as Tiananmen Square in Beijing, the Zócalo in Mexico City, the Piazza Navonae in Rome and Trafalgar Square in London."</ref> Today cities have a [[city center]] or [[downtown]], sometimes coincident with a [[central business district]].

=== Public space ===
[[File:Trafalgar Square, London 2 - Jun 2009.jpg|thumb|[[Trafalgar Square]], a public meeting place in central [[London]] ]]
Cities typically have [[public space]]s where anyone can go. These include [[privately owned public space|privately owned spaces open to the public]] as well as forms of public land such as [[Public domain (land)|public domain]] and the [[common land|commons]]. [[Western philosophy]] since the time of the Greek [[agora]] has considered physical public space as the substrate of the symbolic [[public sphere]].{{sfn | Latham | McCormack | McNamara | McNeill | 2009 | pp=177–179}}<ref>{{Cite journal |last=Mitchell |first=Don |year=1995 |title=The End of Public Space?People's Park, Definitions of the Public, and Democracy |url=https://www.academia.edu/download/33133088/the-end-of-public-space-mitchell.pdf |journal=Annals of the Association of American Geographers |volume=85 |issue=1 |pages=108–133 |doi=10.1111/j.1467-8306.1995.tb01797.xa |doi-broken-date=6 July 2025 }}{{Dead link|date=November 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> [[Public art]] adorns (or disfigures) public spaces. [[Park]]s and other [[Incorporation of nature within a city|natural sites within cities]] provide residents with relief from the hardness and regularity of typical [[built environment]]s. [[Urban green spaces]] are another component of public space that provides the benefit of mitigating the urban heat island effect, especially in cities that are in warmer climates. These spaces prevent carbon imbalances, extreme habitat losses, electricity and water consumption, and human health risks.<ref>{{Cite journal |last1=Li |first1=Xiaoma |last2=Zhou |first2=Weiqi |date=2019-05-01 |title=Optimizing urban greenspace spatial pattern to mitigate urban heat island effects: Extending understanding from local to the city scale |url=https://www.sciencedirect.com/science/article/pii/S1618866718306411 |journal=Urban Forestry & Urban Greening |volume=41 |pages=255–263 |doi=10.1016/j.ufug.2019.04.008 |bibcode=2019UFUG...41..255L |s2cid=149962822 |issn=1618-8667|url-access=subscription }}</ref>

=== Internal structure ===
[[File:L'Enfant plan.svg|thumb |The [[L'Enfant Plan]] for [[Washington, D.C.]] combines a utilitarian grid pattern with diagonal avenues and a symbolic focus on monumental architecture.]]

[[Urban structure|The urban structure]] generally follows one or more basic patterns: geomorphic, radial, concentric, rectilinear, and curvilinear. The physical environment generally constrains the form in which a city is built. If located on a mountainside, urban structures may rely on terraces and winding roads. It may be adapted to its means of subsistence (e.g. agriculture or fishing). And it may be set up for optimal defense given the surrounding landscape.<ref>Moholy-Nagy (1968), 21–33.</ref> Beyond these "geomorphic" features, cities can develop internal patterns, due to natural growth or to [[urban planning|city planning]].

In a radial structure, main roads converge on a central point. This form could evolve from successive growth over a long time, with concentric traces of [[town wall]]s and [[citadel]]s marking older city boundaries. In more recent history, such forms were supplemented by [[ring road]]s moving traffic around the outskirts of a town. Dutch cities such as [[Amsterdam]] and [[Haarlem]] are structured as a central square surrounded by concentric canals marking every expansion. In cities such as [[Moscow]], this pattern is still clearly visible.

A system of rectilinear city streets and land plots, known as the [[grid plan]], has been used for millennia in Asia, Europe, and the Americas. The [[Indus Valley Civilisation|Indus Valley Civilization]] built [[Mohenjo-Daro]], [[Harappa]], and other cities on a grid pattern, using ancient principles described by [[Kautilya]], and aligned with the [[compass points]].<ref>{{cite journal| first1=Mohan| last1=Pant| first2=Shjui| last2=Fumo| title=The Grid and Modular Measures in The Town Planning of Mohenjodaro and Kathmandu Valley. A Study on Modular Measures in Block and Plot Divisions in the Planning of Mohenjodaro and Sirkap (Pakistan), and Thimi (Kathmandu Valley)| journal=Journal of Asian Architecture and Building Engineering| volume=59| issue=4| pages=51–59|year=2005|doi=10.3130/jaabe.4.51|doi-access=free}}</ref><ref name= Smith/><ref>{{Cite journal |last=Danino |first=Matthew |year=2008 |title=New Insights into Harappan Town-Planning, Proportions and Units, with Special Reference to Dholavira |url=http://www.iisc.ernet.in/prasthu/pages/PP_data/paper2.pdf |journal=Man and Environment |volume=33 |issue=1 |pages=66–79 |archive-url=https://web.archive.org/web/20170525012828/http://www.iisc.ernet.in/prasthu/pages/PP_data/paper2.pdf |archive-date=2017-05-25}}</ref><ref>Jane McIntosh, ''The Ancient Indus Valley: New Perspectives''; ABC-CLIO, 2008; {{ISBN|978-1-57607-907-2}}  pp. [https://books.google.com/books?id=1AJO2A-CbccC&pg=PA231 231] {{Webarchive|url=https://web.archive.org/web/20200729144219/https://books.google.com/books?id=1AJO2A-CbccC&pg=PA231 |date=29 July 2020 }}, [https://books.google.com/books?id=1AJO2A-CbccC&pg=PA346 346] {{Webarchive|url=https://web.archive.org/web/20200729134430/https://books.google.com/books?id=1AJO2A-CbccC&pg=PA346 |date=29 July 2020 }}.</ref> The ancient Greek city of [[Priene]] exemplifies a grid plan with specialized districts used across the [[Hellenistic period|Hellenistic Mediterranean]].

=== Urban areas ===
The urban-type settlement extends far beyond the traditional boundaries of the [[city proper]]<ref>Carter (1995), p. 15. "In the underbound city the administratively defined area is smaller than the physical extent of settlement. In the overbound city the administrative area is greater than the physical extent. The 'truebound' city is one where the administrative bound is nearly coincidental with the physical extent."</ref> in a form of development sometimes described critically as [[urban sprawl]].<ref>{{Cite book |year=2013 |author1=Paul James |author2=Meg Holden |author3=Mary Lewin |author4=Lyndsay Neilson |author5=Christine Oakley |author6=Art Truter |author7=David Wilmoth |chapter=Managing Metropolises by Negotiating Mega-Urban Growth |title=Institutional and Social Innovation for Sustainable Urban Development |editor1=Harald Mieg |editor2=Klaus Töpfer |chapter-url=https://www.academia.edu/7207756 |publisher=Routledge |access-date=20 December 2017 |archive-date=16 August 2021 |archive-url=https://web.archive.org/web/20210816025327/https://www.academia.edu/7207756 |url-status=live }}</ref> Decentralization and dispersal of city functions (commercial, industrial, residential, cultural, political) has transformed the very meaning of the term and has challenged geographers seeking to classify territories according to an urban-rural binary.<ref name= Hugo/>

[[Metropolitan area]]s include [[suburb]]s and [[exurb]]s organized around the needs of [[commuting|commuters]], and sometimes [[edge city|edge cities]] characterized by a degree of economic and political independence. (In the US these are grouped into [[metropolitan statistical areas]] for purposes of [[demography]] and [[marketing]].) Some cities are now part of a continuous urban landscape called [[urban agglomeration]], [[conurbation]], or [[megalopolis]] (exemplified by the [[northeast megalopolis|BosWash]] corridor of the [[Northeastern United States]].)<ref>{{Cite journal |last1=Fang |first1=Chuanglin |last2=Yu |first2=Danlin |year=2017 |title=Urban agglomeration: An evolving concept of an emerging phenomenon |journal=Landscape and Urban Planning|volume=162 |pages=126–136 |doi=10.1016/j.landurbplan.2017.02.014 |doi-access=free |bibcode=2017LUrbP.162..126F }}</ref>

==History==
{{Main|History of cities}}

{{Further|Urban history|Historical urban community sizes|List of largest cities throughout history}}
[[File:Oldest arch 4.JPG|thumb|An [[arch]] from the ancient [[Sumer]]ian city [[Ur]], which flourished in the [[third millennium BC]], can be seen at present-day Tell el-Mukayyar in [[Iraq]].]]
[[File:Mohenjo-daro.jpg|thumb|[[Mohenjo-daro]], a city of the [[Indus Valley Civilization]] in Pakistan, which was rebuilt six or more times, using bricks of standard size, and adhering to the same grid layout—also in the third millennium BC]]
[[File:Teotihuacán 2012-09-28 00-07-11.jpg|thumb|Aerial view of what was once downtown [[Teotihuacan]] showing the [[Pyramid of the Sun]], [[Pyramid of the Moon]], and the processional avenue serving as the spine of the city's street system]]
The emergence of cities from [[proto-city|proto-urban settlements]], such as [[Çatalhöyük]], is a non-linear development that demonstrates the varied experiences of early [[urbanization]].<ref>{{Cite journal |last=Mazzucato |first=Camilla |date=2019-05-09 |title=Socio-Material Archaeological Networks at Çatalhöyük a Community Detection Approach |journal=Frontiers in Digital Humanities |volume=6 |article-number=8 |doi=10.3389/fdigh.2019.00008 |issn=2297-2668|doi-access=free }}</ref> The cities of [[Jericho]], [[Aleppo]], [[Byblos]], [[Faiyum]], [[Yerevan]], [[Athens]], [[Matera]], [[Damascus]], and [[Argos, Peloponnese|Argos]] are among those laying claim to [[List of oldest continuously inhabited cities|the longest continual inhabitation]].<ref>{{Cite web |date=2019-02-22 |title=10 oldest cities in the world |url=https://www.educationworld.in/10-oldest-cities-in-the-world/ |access-date=2023-10-26 |website=EducationWorld}}</ref><ref>{{Cite web |title=UNESCO World Heritage Centre – World Heritage List |url=https://whc.unesco.org/en/list/ |access-date=2023-10-26 |website=UNESCO World Heritage Centre}}</ref>

Cities, characterized by [[population density]], [[symbol]]ic function, and [[urban planning]], have existed for thousands of years.<ref>Nick Compton, "What is the oldest city in the world?", ''The Guardian'', 16 February 2015.</ref> In the conventional view, civilization and the city were both followed by the [[Neolithic Revolution|development of agriculture]], which enabled the production of surplus food and thus a social [[division of labour|division of labor]] (with concomitant [[social stratification]]) and [[trade]].<ref>{{Harv |Bairoch|1988| pp=3–4}}</ref><ref>{{Harv |Pacione|2001| p=16}}</ref> Early cities often featured [[granary|granaries]], sometimes within a temple.<ref>Kaplan et al. (2004), p. 26. "Early cities also reflected these preconditions in that they served as places where agricultural surpluses were stored and distributed. Cities functioned economically as centers of extraction and redistribution from countryside to granaries to the urban population. One of the main functions of this central authority was to extract, store, and redistribute the grain. It is no accident that granaries—storage areas for grain—were often found within the temples of early cities."</ref> A minority viewpoint considers that cities may have arisen without agriculture, due to alternative means of subsistence (fishing),<ref>{{cite book |first=Jennifer R. |last=Pournelle |chapter-url=https://www.researchgate.net/publication/257139948 |chapter=KLM to Corona: A Bird's Eye View of Cultural Ecology and Early Mesopotamian Urbanization |title=Settlement and Society: Essays Dedicated to Robert McCormick Adams |editor=Elizabeth C. Stone |publisher=Cotsen Institute of Archaeology, UCLA, and Oriental Institute of the University of Chicago| date=2007-12-31 | isbn=978-1-938770-97-5 | doi=10.2307/j.ctvdjrqjp.8 | pages=29–62}}</ref> to use as communal seasonal shelters,<ref name= Perlman>[[Fredy Perlman |Perlman, Fredy]], ''[[Against His-Story, Against Leviathan]]'', Detroit: Black & Red, 1983; p. 16.</ref> to their value as bases for defensive and offensive military organization,<ref name="Mumfurd1961war" /><ref name="Ashworth1991p12">Ashworth (1991), pp. 12–13.</ref> or to their inherent economic function.<ref name="Jacobs 1969 23">{{Harv |Jacobs|1969| p=23}}</ref><ref>{{cite journal | last=Taylor | first=Peter J. |author-link=Peter J. Taylor | title=Extraordinary Cities: Early 'City-ness' and the Origins of Agriculture and States | journal=International Journal of Urban and Regional Research | volume=36 | issue=3 | date=2012 | issn=0309-1317 | doi=10.1111/j.1468-2427.2011.01101.x | pages=415–447| hdl=10.1111/j.1468-2427.2011.01101.x | hdl-access=free }}; see also GaWC Research Bulletins [http://www.lboro.ac.uk/gawc/rb/rb359.html 359] {{Webarchive|url=https://web.archive.org/web/20171111172356/http://www.lboro.ac.uk/gawc/rb/rb359.html |date=11 November 2017 }} and [http://www.lboro.ac.uk/gawc/rb/rb360.html 360] {{Webarchive|url=https://web.archive.org/web/20171113190604/http://www.lboro.ac.uk/gawc/rb/rb360.html |date=13 November 2017 }}.</ref><ref>{{Cite journal |last1=Smith |first1=Michael E. |last2=Ur |first2=Jason |last3=Feinman |first3=Gary M. |year=2014 |title=Jane Jacobs' 'Cities First' Model and Archaeological Reality |url=https://onlinelibrary.wiley.com/doi/10.1111/1468-2427.12138 |url-status=live |journal=International Journal of Urban and Regional Research|volume=38 |issue=4 |pages=1525–1535 |doi=10.1111/1468-2427.12138 |s2cid=143207540 |issn=0309-1317 |archive-url=https://web.archive.org/web/20171003174652/https://dash.harvard.edu/bitstream/handle/1/13364827/Smith%20etal%202014%20IJURR.pdf?sequence=1 |archive-date=2017-10-03|url-access=subscription }}</ref> Cities played a crucial role in the establishment of political power over an area, and ancient leaders such as [[Alexander the Great]] founded and created them with zeal.<ref>McQuillan (1937/1987), §1.03. "The ancients fostered the spread of urban culture; their efforts were constant to bring their people within the complete influence of municipal life. The desire to create cities was the most striking characteristic of the people of antiquity, and ancient rulers and statesmen vied with one another in satisfying that desire."</ref>

=== Ancient times ===
{{Further|Cities of the Ancient Near East|Polis|City-state|Late Antiquity#Cities}}
{{redirect|Ancient city}}
[[File:Artgate Fondazione Cariplo - Betti Oreste - Veduta della Roma imperiale.jpg|thumb|A modern depiction of [[Ancient Rome]], the first city in the world to reach one million inhabitants]]
[[Tell es-Sultan|Jericho]] and [[Çatalhöyük]], dated to the [[eighth millennium BC]], are among the earliest [[proto-cities]] known to archaeologists.<ref name= Perlman/><ref>Southall (1998), p. 23.</ref> However, the [[Mesopotamia]]n city of [[Uruk]] from the mid-fourth millennium BC (ancient Iraq) is considered by most archaeologists to be the first true city, innovating many characteristics for cities to follow, with its name attributed to the [[Uruk period]].<ref>{{Cite web |last=Department of Ancient Near Eastern Art |date=Oct 2003 |title=Uruk: The First City |url=https://www.metmuseum.org/toah/hd/uruk/hd_uruk.htm |access-date=5 March 2022 |website=The Metropolitan Museum of Art |archive-date=1 April 2020 |archive-url=https://web.archive.org/web/20200401115230/https://www.metmuseum.org/toah/hd/uruk/hd_uruk.htm |url-status=live }}</ref><ref>{{Cite web |title=Uruk (article) |url=https://www.khanacademy.org/humanities/big-history-project/agriculture-civilization/first-cities-states/a/uruk |access-date=5 March 2022 |website=Khan Academy|archive-date=5 March 2022 |archive-url=https://web.archive.org/web/20220305140202/https://www.khanacademy.org/humanities/big-history-project/agriculture-civilization/first-cities-states/a/uruk |url-status=live }}</ref><ref>{{Cite web |title=What Science Has Learned about the Rise of Urban Mesopotamia |url=https://www.thoughtco.com/uruk-period-mesopotamia-rise-of-sumer-171676 |access-date=5 March 2022 |website=ThoughtCo| archive-date=5 March 2022 |archive-url=https://web.archive.org/web/20220305135740/https://www.thoughtco.com/uruk-period-mesopotamia-rise-of-sumer-171676 |url-status=live }}</ref>

In the [[fourth millennium BC|fourth]] and [[third millennium BC]], complex civilizations flourished in the river valleys of [[Mesopotamia]], [[India]],<ref>{{cite book |last1=Ring |first1=Trudy |title=Middle East and Africa: International Dictionary of Historic Places |date=2014 |isbn=978-1-134-25986-1 |page=204|publisher=Routledge }}</ref><ref>{{cite news |first=Jhimli Mukherjee |last=Pandeyl |title=Varanasi is as old as Indus valley civilization, finds IIT-KGP study |work=[[The Times of India]] |date=25 February 2016}}</ref> [[China]],<ref>{{Cite magazine |title=Where was the first city in the world? |url=https://www.newscientist.com/question/first-cities-built/ |access-date=2023-05-22 |magazine=[[New Scientist]]}}</ref> and [[Egypt]]. Excavations in these areas have found the [[ruins]] of cities geared variously towards trade, politics, or religion. Some had large, [[Urban density|dense populations]], but others carried out urban activities in the realms of politics or religion without having large associated populations.

Among the early Old World cities, [[Mohenjo-daro]] of the Indus Valley civilization in present-day [[Pakistan]], existing from about 2600 BC, was one of the largest, with a population of 50,000 or more and a [[Sanitation of the Indus Valley Civilisation|sophisticated sanitation system]].<ref>{{Cite book |last=Kenoyer |first=Jonathan Mark |title=Ancient Cities of the Indus Valley Civilization |publisher=[[Oxford University Press]] |year=1998 |isbn=978-0-19-577940-0 |edition=2nd |location=Karachi and New York|editor-last2=}}</ref> [[Ancient Chinese urban planning|China's planned cities]] were constructed according to sacred principles to act as celestial [[Macrocosm and microcosm|microcosms]].<ref>Southall (1998), pp. 38–43.</ref>

The [[List of ancient Egyptian towns and cities|Ancient Egyptian cities]] known physically by archaeologists are not extensive.<ref name= Smith/> They include (known by their Arab names) [[El Lahun]], a workers' town associated with the pyramid of [[Senusret II]], and the religious city [[Amarna]] built by [[Akhenaten]] and abandoned. These sites appear planned in a highly regimented and [[social stratification|stratified]] fashion, with a minimalistic grid of rooms for the workers and increasingly more elaborate housing available for higher classes.<ref>Moholy-Nagy (1968), pp. 158–161.</ref>

In Mesopotamia, the civilization of [[Sumer]], followed by [[Assyria]] and [[Babylon]], gave rise to numerous cities, governed by kings and fostered multiple languages written in [[cuneiform]].<ref>{{Cite book |last=Adams |first=Robert McCormick |url=https://isac.uchicago.edu/sites/default/files/uploads/shared/docs/heartland_of_cities.pdf |title=Heartland of cities: surveys of ancient settlement and land use on the central floodplain of the Euphrates |date=1981 |publisher=University of Chicago press |isbn=978-0-226-00544-7 |location=Chicago and London |page=2 |quote=Southern Mesopotamia was a land of cities. It became one precociously, before the end of the fourth millennium B.C. Urban traditions remained strong and virtually continuous through the vicissitudes of conquest, internal upheaval accompanied by widespread economic breakdown, and massive linguistic and population replacement. The symbolic and material content of civilization obviously changed, but its cultural ambience remained tied to cities. |author-link=Robert McCormick Adams Jr. |archive-url=https://web.archive.org/web/20181113035705/https://oi.uchicago.edu/sites/oi.uchicago.edu/files/uploads/shared/docs/heartland_of_cities.pdf |archive-date=2018-11-13 |url-status=live}}</ref> The [[Phoenicia]]n trading empire, flourishing around the turn of the [[first millennium BC]], encompassed [[List of Phoenician cities|numerous cities]] extending from [[Tyre, Lebanon|Tyre]], [[Cydon]], and [[Byblos]] to [[Carthage]] and [[Cádiz]].

In the following centuries, independent [[city-state]]s of [[Ancient Greece|Greece]], especially [[Classical Athens|Athens]], developed the ''[[polis]]'', an association of male landowning [[citizenship|citizens]] who collectively constituted the city.<ref name="tws2Y21">{{Cite book | last = Pocock | first = J.G.A. | title = The Citizenship Debates | publisher = The University of Minnesota | series = Chapter 2 – The Ideal of Citizenship since Classical Times (originally published in ''Queen's Quarterly'' 99, no. 1) | year = 1998 | location = Minneapolis, MN | page = 31 | url = https://books.google.com/books?id=i6U7CTuCJLYC&pg=PA31 | isbn = 978-0-8166-2880-3 | access-date = 11 November 2015 | archive-date = 9 June 2016 | archive-url = https://web.archive.org/web/20160609220358/https://books.google.com/books?id=i6U7CTuCJLYC&pg=PA31 | url-status = live }}</ref> The [[agora]], meaning "gathering place" or "assembly", was the center of the athletic, artistic, spiritual, and political life of the polis.<ref name="InternationalDictionary">{{cite book |title = International Dictionary of Historic Places: Southern Europe | last1=Ring |last2=Salkin |last3=Boda | first1=Trudy |first2=Robert |first3=Sharon | publisher = Routledge|date = 1996 | page = 66 | isbn=978-1-884964-02-2}}</ref> [[Rome]] was the first city that surpassed one million inhabitants. Under the authority of [[Roman Empire|its empire]], Rome transformed and [[List of cities founded by the Romans|founded]] many cities ({{lang|la|[[Colonia (Roman)|Colonia]]}}), and with them brought its principles of urban architecture, design, and society.<ref>Kaplan et al. (2004), pp. 41–42. "Rome created an elaborate urban system. Roman colonies were organized as a means of securing Roman territory. The first thing that Romans did when they conquered new territories was to establish cities."</ref>

In the ancient [[Americas]], early urban traditions developed in the [[Andes]] and [[Mesoamerica]]. In the Andes, the first urban centers developed in the [[Norte Chico civilization]], [[Chavín culture|Chavin]] and [[Moche (culture)|Moche]] cultures, followed by major cities in the [[Huari culture|Huari]], [[Chimu]], and [[Inca]] cultures. The Norte Chico civilization included as many as 30 major population centers in what is now the [[Norte Chico (Peruvian region)|Norte Chico region]] of north-central coastal [[Peru]]. It is the oldest known civilization in the Americas, flourishing between the 30th and 18th centuries BC.<ref name="Shady1997">{{cite book |last=Shady Solís |first=Ruth Martha |author-link=Ruth Shady |title=La ciudad sagrada de Caral-Supe en los albores de la civilización en el Perú |url=http://sisbib.unmsm.edu.pe/Bibvirtual/Libros/Arqueologia/ciudad_sagrada/caratula.htm |access-date=3 March 2007 |year=1997 |publisher=UNMSM, Fondo Editorial |location=Lima |language=es |archive-date=7 February 2009 |archive-url=https://web.archive.org/web/20090207051615/http://sisbib.unmsm.edu.pe/Bibvirtual/libros/Arqueologia/ciudad_sagrada/caratula.htm |url-status=live }}</ref> Mesoamerica saw the rise of early urbanism in several cultural regions, beginning with the [[Olmec]] and spreading to the [[Maya city|Preclassic Maya]], the [[Zapotec civilization|Zapotec]] of Oaxaca, and [[Teotihuacan]] in central Mexico. Later cultures such as the [[Aztec]], [[Andean civilization]]s, [[Maya peoples|Mayan]], [[Mississippian culture|Mississippians]], and [[Pueblo]] peoples drew on these earlier urban traditions. Many of their ancient cities continue to be inhabited, including major metropolitan cities such as [[Mexico City]], in the same location as [[Tenochtitlan]]; while ancient continuously inhabited Pueblos are near modern urban areas in [[New Mexico]], such as [[Acoma Pueblo]] near the [[Albuquerque metropolitan area]] and [[Taos Pueblo]] near [[Taos, New Mexico|Taos]]; while others like [[Lima]] are located nearby ancient [[Peru]]vian sites such as [[Pachacamac]].

From 1600 BC, [[Dhar Tichitt]], in the south of present-day [[Mauritania]], presented characteristics suggestive of an incipient form of urbanism.<ref name="Monroe, J. Cameron 2017">{{cite journal|author=Monroe, J. Cameron|title="Elephants for Want of Towns": Archaeological Perspectives on West African Cities and Their Hinterlands |journal=Journal of Archaeological Research|date=2018 |volume=26 |issue=4 |pages=387–446|doi=10.1007/s10814-017-9114-2}}</ref><ref name="MacDonald, Kevin 2015">{{Cite book|title=The Cambridge World History.|last=MacDonald|first=Kevin|publisher=Cambridge University Press|year=2015|editor-last1=Barker|editor-first1=Graeme|editor-last2=Barker|editor-first2=Candice|location=Cambridge, United Kingdom|pages=409–513|chapter=The Tichitt tradition in the West African Sahel}}</ref> The second place to show urban characteristics in [[West Africa]] was [[Dia, Mali|Dia]], in present-day [[Mali]], from 800 BC.<ref name="Monroe, J. Cameron 2017" /><ref name="MacDonald, Kevin 2015" /> Both Dhar Tichitt and Dia were founded by the same people: the [[Soninke people|Soninke]], who would later also found the [[Ghana Empire]].<ref name="MacDonald, Kevin 2015" />

Another ancient site, [[Jenné-Jeno]], in what is today [[Mali]], has been dated to the third century BCE. According to Roderick and Susan McIntosh, Jenné-Jeno did not fit into traditional Western conceptions of urbanity as it lacked monumental architecture and a distinctive elite social class, but it should indeed be considered a city based on a functional redefinition of urban development. In particular, Jenné-Jeno featured settlement mounds arranged according to a horizontal, rather than vertical, power hierarchy, and served as a center of specialized production and exhibited functional interdependence with the surrounding hinterland.<ref>McIntosh, Roderic J., McIntosh, Susan Keech. "Early Urban Configurations on the Middle Niger: Clustered Cities and Landscapes of Power," Chapter 5.</ref>

More recently, scholars have concluded that the [[civilization]] of Djenne-Djenno was likely established by the [[Mandé peoples|Mande]] progenitors of the [[Bozo people]]. Their habitation of the site spanned the period from 3rd century BCE to 13th century CE.<ref name="Vydrin">{{cite web |last1=Vydrin |first1=Valentin |title=Mande Languages |url=https://oxfordre.com/linguistics/view/10.1093/acrefore/9780199384655.001.0001/acrefore-9780199384655-e-397 |website=Oxford Research Encyclopedia of Linguistics |year=2018 |publisher=Oxford University Press|doi=10.1093/acrefore/9780199384655.013.397 |isbn=978-0-19-938465-5 }}</ref> Archaeological evidence from Jenné-Jeno, specifically the presence of non-West African glass beads dated from the third century BCE to the fourth century CE, indicates that pre-Arabic trade contacts probably existed between Jenné-Jeno and North Africa.<ref name=Magnavita>{{cite journal|last=Magnavita|first=Sonja|title=Initial Encounters: Seeking traces of ancient trade connections between West Africa and the wider world|url=http://afriques.revues.org/1145?lang=en|journal=Afriques|year=2013|volume=04 |issue=4|doi=10.4000/afriques.1145|access-date=December 13, 2013|doi-access=free}}</ref>

Additionally, other early urban centers in West Africa, dated to around 500 CE, include [[Aoudaghost|Awdaghust]], [[Koumbi Saleh|Kumbi Saleh]], the ancient capital of Ghana, and [[:de:Marandet|Maranda]], a center located on a trade route between Egypt and Gao.<ref>''[http://markuswiener.com/book_reviews.html?products_id=93&products_name=History%20of%20African%20Cities%20South%20of%20the%20Sahara History of African Cities South of the Sahara] {{webarchive|url=https://web.archive.org/web/20080124191535/http://markuswiener.com/book_reviews.html?products_id=93&products_name=History%20of%20African%20Cities%20South%20of%20the%20Sahara |date=2008-01-24 }}'' By Catherine Coquery-Vidrovitch. 2005. {{ISBN|1-55876-303-1}}</ref>

===Middle Ages===
[[File:Vyborg SevernyVal3-5 006 8242.jpg|thumb|[[Vyborg]] in Leningrad Oblast has existed since the 13th century.]]
[[File:Monumentale torens in de binnenstad.jpg|thumb|upright=.7|Old city of [[Utrecht]], Netherlands]]
[[File:Holy Roman Empire 1648 Imperial cities.png|thumb|The [[Free imperial city|Free imperial cities]] of the [[Holy Roman Empire]] in 1648]]
[[File:Haarlem-City-Map-1550.jpg|thumb|A map of [[Haarlem]] in the Netherlands, created around 1550, shows the city completely surrounded by a [[defensive wall|city wall]] and [[moat|defensive canal]], with its square shape inspired by the shape of [[Jerusalem]].]]
The [[Fall of the Western Roman Empire|dissolution of the Roman Empire]] in the West was connected with profound changes in urban fabric of western Europe.<ref>{{Cite book |last=Wickham |first=Chris |title=Framing the early Middle Ages: Europe and the Mediterranean 400-800 |date=2006 |publisher=Oxford University Press |isbn=978-0-19-921296-5 |edition=First published in paperback |location=Oxford New York, NY |pages=591–692}}</ref> In places where Roman administration quickly weakened urbanism went through a profound crisis, even if it continued to remain an important symbolic factor.<ref>{{Cite book |last=Fafinski |first=Mateusz |title=Roman infrastructure in early medieval Britain: the adaptations of the past in text and stone |date=2021 |publisher=Amsterdam University Press |isbn=978-90-485-5197-2 |series=Early medieval North Atlantic |location=Amsterdam |pages=83–142}}</ref> In regions like Italy or Spain cities diminished in size but nevertheless continued to play a key role in both the economy and government.<ref>{{Cite journal |last=Osland |first=Daniel |date=2023-09-02 |title=The Role of Cities in the Early Medieval Economy |journal=Al-Masāq |language=en |volume=35 |issue=3 |pages=343–363 |doi=10.1080/09503110.2023.2211882 |issn=0950-3110|doi-access=free }}</ref> [[Late antiquity#Cities|Late antique cities]] in the East were also undergoing intense transformations, with increased political participation of the crowds and demographic fluctuations.<ref>{{Cite journal |last=de Oliveira |first=Julio Cesar Magalhães |date=2020-11-01 |title=Late Antiquity: The Age of Crowds?* |url=https://academic.oup.com/past/article/249/1/3/5819584 |journal=Past & Present |language=en |issue=249 |pages=3–52 |doi=10.1093/pastj/gtz063 |issn=0031-2746|url-access=subscription }}</ref> Christian communities and their doctrinal differences increasingly shaped the urban fabric.<ref>{{Cite journal |last=Fafinski |first=Mateusz |date=2024-04-04 |title=A Restless City: Edessa and Urban Actors in the Syriac Acts of the Second Council of Ephesus |journal=Al-Masāq |language=en |pages=1–25 |doi=10.1080/09503110.2024.2331915 |issn=0950-3110|doi-access=free }}</ref> The locus of power shifted to [[Constantinople]] and to the [[Early Muslim conquests|ascendant Islamic civilization]] with its major cities [[Baghdad]], [[Cairo]], and [[Córdoba, Spain|Córdoba]].<ref>Kaplan et al. (2004), p. 43. "Capitals like Córdoba and Cairo had populations of about 500,000; Baghdad probably had a population of more than 1 million. This urban heritage would continue despite the conquests of the Seljuk Turks and the later Crusades. China, the longest standing civilization, was in the midst of a golden age as the Tang dynasty gave way—after a short period of fragmentation—to the Song dynasty. This dynasty ruled two of the most impressive cities on the planet, Xian and Hangzhou. / In contrast, poor Western Europe had not recovered from the sacking of Rome and the collapse of the western half of the Roman Empire. For more than five centuries a steady process of deurbanization—whereby the population living in cities and the number of cities declined precipitously—had converted a prosperous landscape into a scary wilderness, overrun with bandits, warlords, and rude settlements."</ref> From the 9th through the end of the 12th century, [[Constantinople]], the capital of the [[Eastern Roman Empire]], was the largest and wealthiest city in Europe, with a population approaching 1 million.<ref>{{Cite book|last=Cameron|first=Averil|title=The Byzantines|page=47|url=https://books.google.com/books?id=59c6PSa5JCAC|publisher=John Wiley and Sons|year=2009|isbn=978-1-4051-9833-2|access-date=24 January 2015|archive-date=23 May 2020|archive-url=https://web.archive.org/web/20200523031336/https://books.google.com/books?id=59c6PSa5JCAC|url-status=live}}</ref><ref>{{Cite book|last=Laiou |first=Angeliki E. |author-link=Angeliki Laiou |title=The Economic History of Byzantium (Volume 1) |pages=130–131 |year=2002 |location=Washington, DC |publisher=Dumbarton Oaks |editor=Angeliki E. Laiou |chapter=Writing the Economic History of Byzantium |chapter-url=http://www.doaks.org/publications/doaks_online_publications/EHB.html |access-date=6 June 2012 |archive-date=18 February 2012 |archive-url=https://web.archive.org/web/20120218231151/http://www.doaks.org/publications/doaks_online_publications/EHB.html}}</ref> The [[Ottoman Empire]] gradually gained [[List of cities conquered by the Ottoman Empire|control over many cities]] in the Mediterranean area, including [[Fall of Constantinople|Constantinople in 1453]].

In the [[Holy Roman Empire]], beginning in the 12th century, [[free imperial city|free imperial cities]] such as [[Nuremberg]], [[Strasbourg]], [[Frankfurt]], [[Basel]], [[Zürich]], and [[Nijmegen]] became a privileged elite among towns having won self-governance from their local lord or having been granted self-governance by the emperor and being placed under his immediate protection. By 1480, these cities, as far as still part of the empire, became part of the [[Imperial Estates]] governing the empire with the emperor through the [[Imperial Diet (Holy Roman Empire)|Imperial Diet]].<ref>{{cite web|url=https://www.encyclopedia.com/history/encyclopedias-almanacs-transcripts-and-maps/free-and-imperial-cities|title=Free and Imperial Cities – Dictionary definition of Free and Imperial Cities|website=encyclopedia.com|access-date=29 May 2018|archive-date=29 May 2018|archive-url=https://web.archive.org/web/20180529203824/https://www.encyclopedia.com/history/encyclopedias-almanacs-transcripts-and-maps/free-and-imperial-cities|url-status=live}}</ref>

By the 13th and 14th centuries, some cities had become powerful states, taking surrounding areas under their control or establishing extensive maritime empires. In Italy, [[medieval commune]]s developed into [[Italian city-states|city-states]] including the [[Republic of Venice]] and the [[Republic of Genoa]]. In Northern Europe, cities including [[Lübeck]] and [[Bruges]] formed the [[Hanseatic League]] for collective defense and commerce. Their power was later [[Dutch–Hanseatic War|challenged]] and eclipsed by the [[Burgundian Netherlands|Dutch]] commercial [[History of urban centers in the Low Countries|cities]] of [[Ghent]], [[Ypres]], and [[Amsterdam]].<ref>Kaplan et al. (2004), pp. 47–50.</ref> Similar phenomena existed elsewhere, as in the case of [[Sakai, Osaka|Sakai]], which enjoyed considerable autonomy in late medieval Japan.

In the first millennium AD, the [[Khmer Empire|Khmer]] capital of [[Angkor]] in Cambodia grew into the most extensive [[Pre-industrial society|preindustrial settlement]] in the world by area,<ref name="Evans PNAS">Evans ''et al.'', [http://www.pnas.org/content/104/36/14277 A comprehensive archaeological map of the world's largest preindustrial settlement complex at Angkor, Cambodia] {{Webarchive|url=https://web.archive.org/web/20170422171845/http://www.pnas.org/content/104/36/14277 |date=22 April 2017 }}, Proceedings of the National Academy of Sciences of the US, 23 August 2007.</ref><ref name="BBC News 2007">"[http://news.bbc.co.uk/2/hi/science/nature/6945574.stm Map reveals ancient urban sprawl] {{Webarchive|url=https://web.archive.org/web/20071028014349/http://news.bbc.co.uk/2/hi/science/nature/6945574.stm |date=28 October 2007 }}", BBC News, 14 August 2007.</ref> covering over {{Convert|1000|km2|abbr=on}} and possibly supporting up to one million people.<ref name="Evans PNAS" /><ref>[https://www.independent.co.uk/news/world/asia/metropolis-angkor-the-worlds-first-megacity-461623.html Metropolis: Angkor, the world's first mega-city] {{Webarchive|url=https://web.archive.org/web/20110919133524/http://www.independent.co.uk/news/world/asia/metropolis-angkor-the-worlds-first-megacity-461623.html |date=19 September 2011}}, The Independent, 15 August 2007</ref>

[[West Africa]] already had cities before the [[Common Era]], but the consolidation of [[Trans-Saharan trade]] in the Middle Ages multiplied the number of cities in the region, as well as making some of them very populous, notably [[Gao]] (72,000 inhabitants in 800 AD), [[Old Oyo|Oyo-Ile]] (50,000 inhabitants in 1400 AD, and may have reached up to 140,000 inhabitants in the 18th century), [[Ifẹ̀|Ile-Ifẹ̀]] (70,000 to 105,000 inhabitants in the 14th and 15th centuries), [[Niani, Guinea|Niani]] (50,000 inhabitants in 1400 AD) and [[Timbuktu]] (100,000 inhabitants in 1450 AD).<ref name="Monroe, J. Cameron 2017" /><ref>''[https://www.african-cities.org/african-cities-from-500-ad-to-1900/ African cities from 500 AD to 1900] {{Webarchive|url=https://web.archive.org/web/20220217094302/https://www.african-cities.org/african-cities-from-500-ad-to-1900/ |date=17 February 2022 }}'' By David Satterthwaite. 2021.</ref>

===Early modern===
In the West, nation-states became the dominant unit of political organization following the [[Peace of Westphalia]] in the seventeenth century.<ref>Curtis (2016), pp. 5–6. "In the modern international system, cities were subjugated and internalized by the state, and, with industrialization, became the great growth engines of national economies."</ref><ref name="Blomley2013">[[Nicholas Blomley]], "What Sort of a Legal Space is a City?" in Brighenti (2013), pp. 1–20. "Municipalities, within this frame, are understood as nested within the jurisdictional space of the provinces. Indeed, rather than freestanding legal sites, they are imagined as products (or 'creatures') of the provinces who may bring them into being or dissolve them as they choose. As with the provinces their powers are of a delegated form: they may only exercise jurisdiction over areas that have been expressly identified by enabling legislation. Municipal law may not conflict with provincial law, and may only be exercised within its defined territory. [...] <br /> Yet we are [in] danger [of] missing the reach of municipal law: '[e]ven in highly constitutionalized regimes, it has remained possible for municipalities to micro-manage space, time, and activities through police regulations that infringe both on constitutional rights and private property in often extreme ways' (Vaverde 2009: 150). While liberalism fears the encroachments of the state, it seems less worried about those of the municipality. Thus if a national government proposed a statute forbidding public gatherings or sporting events, a revolution would occur. Yet municipalities routinely enact sweeping by-laws directed at open ended (and ill-defined) offences such as loitering and obstruction, requiring permits for protests or requiring residents and homeowners to remove snow from the city's sidewalks."</ref> Western Europe's larger capitals (London and Paris) benefited from the growth of commerce following the emergence of an [[Atlantic Ocean|Atlantic]] trade. However, most towns remained small.

During the Spanish colonization of the Americas, the old Roman city concept was extensively used. Cities were founded in the middle of the newly conquered territories and were bound to several laws regarding administration, finances, and urbanism.

===Industrial age===

The [[Industrial Revolution|growth of the modern industry]] from the late 18th century onward led to massive [[urbanization]] and the rise of new great cities, first in Europe and then in other regions, as new opportunities brought huge numbers of migrants from rural communities into urban areas. England led the way as [[London]] became the capital of a [[British Empire|world empire]] and cities across the country grew in locations strategic for [[manufacturing]].<ref>Kaplan et al. (2004), pp. 53–54. "England was clearly at the center of these changes. London became the first truly global city by placing itself within the new global economy. English colonialism in North America, the Caribbean, South Asia, and later Africa and China helped to further fatten the wallets of many of its merchants. These colonies would later provide many of the raw materials for industrial production. England's hinterland was no longer confined to a portion of the world; it effectively became a global hinterland."</ref> In the United States from 1860 to 1910, the [[History of rail transport|introduction of railroads]] reduced transportation costs, and large manufacturing centers began to emerge, fueling migration from rural to city areas.

Some industrialized cities were confronted with health challenges associated with [[overcrowding]], [[occupational hazard]]s of industry, contaminated water and air, [[History of water supply and sanitation#Modern age|poor sanitation]], and communicable diseases such as [[typhoid]] and [[cholera]]. [[Factories]] and [[slum]]s emerged as regular features of the urban landscape.<ref>Kaplan et al. (2004), pp. 54–55.</ref>

===Post-industrial age===
In the second half of the 20th century, [[deindustrialization]] (or "[[economic restructuring]]") in the West led to [[poverty]], [[homelessness]], and [[urban decay]] in formerly prosperous cities. America's "Steel Belt" became a "[[Rust Belt]]" and cities such as [[Decline of Detroit|Detroit]], Michigan, and [[Gary, Indiana]] began to [[Shrinking cities|shrink]], contrary to the global trend of massive urban expansion.<ref>Steven High, ''[https://archive.org/details/industrialsunset0000high/page/5 Industrial Sunset: The Making of North America's Rust Belt, 1969–1984]''; University of Toronto Press, 2003; {{ISBN|0-8020-8528-8}}. "It is now clear that the deindustrialization thesis is part myth and part fact. Robert Z. Lawrence, for example, uses aggregate economic data to show that manufacturing employment in the United States did not decline but actually increased from 16.8&nbsp;million in 1960, to 20.1&nbsp;million in 1973, and 20.3&nbsp;million in 1980. However, manufacturing employment was in relative decline. Barry Bluestone noted that manufacturing represented a decreasing proportion of the U.S. labour force, from 26.2 per cent in 1973 to 22.1 per cent in 1980. Studies in Canada have likewise shown that manufacturing employment was only in relative decline during these years. Yet mills and factories did close, and towns and cities lost their industries. John Cumbler submitted that 'depressions do not manifest themselves only at moments of national economic collapse' such as in the 1930s, but 'also recur in scattered sites across the nation in regions, in industries, and in communities.{{'"}}</ref> Such cities have shifted with varying success into the [[service economy]] and [[public-private partnerships]], with concomitant [[gentrification]], uneven [[urban renewal|revitalization efforts]], and selective cultural development.<ref name= Kaplan164>Kaplan (2004), pp. 160–165. "Entrepreneurial leadership became manifest through growth coalitions made up of builders, realtors, developers, the media, government actors such as mayors, and dominant corporations. For example, in St. Louis, Anheuser-Busch, Monsanto, and Ralston Purina played prominent roles. The leadership involved cooperation between public and private interests. The results were efforts at downtown revitalization; inner-city gentrification; the transformation of the CBD to advanced service employment; entertainment, museums, and cultural venues; the construction of sports stadiums and sport complexes; and waterfront development."</ref> Under the [[Great Leap Forward]] and subsequent [[Five-year plans of China|five-year plans]] continuing today, [[China]] has undergone concomitant [[urbanization in China|urbanization]] and [[Chinese industrialization|industrialization]] and become the world's leading [[manufacturing|manufacturer]].<ref>James Xiaohe Zhang, "Rapid urbanization in China and its impact on the world economy"; 16th Annual Conference on Global Economic Analysis, "New Challenges for Global Trade in a Rapidly Changing World", Shanhai Institute of Foreign Trade, 12–14 June 2013.</ref><ref>Ian Johnson, "[https://www.nytimes.com/2013/06/16/world/asia/chinas-great-uprooting-moving-250-million-into-cities.html China's Great Uprooting: Moving 250 Million Into Cities] {{Webarchive|url=https://web.archive.org/web/20170829234450/http://www.nytimes.com/2013/06/16/world/asia/chinas-great-uprooting-moving-250-million-into-cities.html |date=29 August 2017 }}"; ''The New York Times'', 15 June 2013.</ref>

Amidst these economic changes, [[high technology]] and instantaneous [[telecommunication]] enable select cities to become centers of the [[knowledge economy]].<ref>{{Cite book |last=Castells |first=Manuel |title=The network society: a cross-cultural perspective |date=2004 |publisher=E. Elgar |isbn=978-1-84376-505-9 |location=London}}</ref><ref>Flew, T. (2008). ''New media: an introduction'', 3rd edn, South Melbourne: Oxford University Press</ref><ref>Harford, T. (2008) ''The Logic of Life''. London: Little, Brown.</ref> A new [[smart city]] paradigm, supported by institutions such as the [[RAND Corporation]] and [[IBM]], is bringing computerized [[Surveillance issues in smart cities|surveillance]], data analysis, and [[E-governance|governance]] to bear on cities and city dwellers.<ref>{{Cite journal |last1=Shelton |first1=Taylor |last2=Zook |first2=Matthew |last3=Wiig |first3=Alan |date=2014-10-27 |title=The 'actually existing smart city' |journal=Cambridge Journal of Regions, Economy and Society|volume=8 |issue=1 |pages=13–25 |doi=10.1093/cjres/rsu026 |issn=1752-1378 |doi-access=free }}</ref> Some companies are building brand-new [[land use planning|master-planned]] cities from scratch on [[greenfield land|greenfield]] sites.

== Urbanization ==
{{Main|Urbanization}}

[[File:Historical global urban - rural population trends.png|thumb|Graph showing urbanization from 1950 projected to 2050<ref>{{cite web|url=https://esa.un.org/unpd/wup/|title=United Nations, Department of Economic and Social Affairs, Population Division (2014). World Urbanization Prospects|format= CD-ROM|archive-url=https://web.archive.org/web/20180706115325/https://esa.un.org/unpd/wup/|archive-date=6 July 2018}}</ref>]]
[[File:2020 1million cities.jpg|thumb|Map showing urban areas with at least one million inhabitants in 2020]]
[[Urbanization]] is the process of migration from rural to urban areas, driven by various political, economic, and cultural factors. Until the 18th century, an equilibrium existed between the rural agricultural population and towns featuring [[Market (place)|markets]] and small-scale manufacturing.<ref>[https://www.academia.edu/26447633/The_Urbanization_and_Political_Development_of_the_World_System_A_comparative_quantitative_analysis The Urbanization and Political Development of the World System:A comparative quantitative analysis. ''History & Mathematics'' 2 (2006): 115–153] {{Webarchive|url=https://web.archive.org/web/20190518123528/https://www.academia.edu/26447633/The_Urbanization_and_Political_Development_of_the_World_System_A_comparative_quantitative_analysis |date=18 May 2019 }}.</ref><ref name="FreyZimmer2001">William H. Frey & Zachary Zimmer, "Defining the City"; in Paddison (2001).</ref> With the [[British Agricultural Revolution|agricultural]] and [[Industrial Revolution|industrial]] revolutions, urban population began its unprecedented growth, both through migration and [[Demographic transition|demographic expansion]]. In [[England]], the proportion of the population living in cities jumped from 17% in 1801 to 72% in 1891.<ref name="urbanization">Watson, Christopher. "[http://www.icup.org.uk/reports/ICUP601.pdf Trends in urbanization] {{Webarchive|url=https://web.archive.org/web/20160305100017/http://icup.org.uk/reports/icup601.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://icup.org.uk/reports/icup601.pdf |archive-date=2022-10-09 |url-status=live |date=2016-03-05 }}", ''[http://www.icup.org.uk/icupindex.asp?CID=1 Proceedings of the First International Conference on Urban Pests] {{Webarchive|url=https://web.archive.org/web/20171010005338/http://www.icup.org.uk/icupindex.asp?CID=1 |date=10 October 2017 }}'', ed. K.B. Wildey and William H. Robinson, 1993.</ref> In 1900, 15% of the world's population lived in cities.<ref>{{cite book|last1=Annez|first1=Patricia Clarke|last2=Buckley|first2=Robert M.|chapter=Urbanization and Growth: Setting the Context|chapter-url=http://www2.lawrence.edu/fast/finklerm/chapter1urban.pdf|title=Urbanization and Growth|editor1-last=Spence|editor1-first=Michael|editor2-last=Annez|editor2-first=Patricia Clarke|editor3-last=Buckley|editor3-first=Robert M.|isbn=978-0-8213-7573-0|year=2009|publisher=Commission on Growth and Development |access-date=20 May 2017|archive-date=25 May 2017|archive-url=https://web.archive.org/web/20170525012907/http://www2.lawrence.edu/fast/finklerm/chapter1urban.pdf|url-status=live}}</ref> The cultural appeal of cities also plays a role in attracting residents.<ref name="MoholyNagy1968p136" />

Urbanization rapidly spread across Europe and the Americas and since the 1950s has taken hold in Asia and Africa as well. The Population Division of the [[United Nations Department of Economic and Social Affairs]] reported in 2014 that for the first time, more than half of the world population lives in cities.<ref name="SenguptaUN2014">Somini Sengupta, "[https://www.nytimes.com/2014/07/11/world/more-than-half-the-global-population-growth-is-urban-united-nations-report-finds.html U.N. Finds Most People Now Live in Cities] {{Webarchive|url=https://web.archive.org/web/20170705095538/https://www.nytimes.com/2014/07/11/world/more-than-half-the-global-population-growth-is-urban-united-nations-report-finds.html |date=5 July 2017 }}"; ''The New York Times'', 10 July 2014. Referring to: United Nations Department of Economic and Social Affairs, Population Division; ''[https://esa.un.org/unpd/wup/ World Urbanization Prospects: 2014 Revision] {{Webarchive|url=https://web.archive.org/web/20180706115325/https://esa.un.org/unpd/wup/ |date=6 July 2018 }}''; New York: United Nations, 2014.</ref>{{efn|Intellectuals such as [[H. G. Wells]], [[Patrick Geddes]] and [[Kingsley Davis]] foretold the coming of a mostly urban world throughout the twentieth century.<ref name=BrennerSchmid2013>{{cite journal | last1=Brenner | first1=Neil | last2=Schmid | first2=Christian | title=The 'Urban Age' in Question | journal=International Journal of Urban and Regional Research | volume=38 | issue=3 | date=2014 | issn=0309-1317 | doi=10.1111/1468-2427.12115 | pages=731–755}}</ref><ref>McQuillin (1937/1987), §1.55.</ref> The United Nations has long anticipated a half-urban world, earlier predicting the year 2000 as the turning point<ref>"[https://esa.un.org/unpd/wup/Archive/Files/studies/United%20Nations%20(1980)%20-%20Patterns%20of%20Urban%20and%20Rural%20Population%20Growth.pdf Patterns of Urban and Rural Population Growth] {{Webarchive|url=https://web.archive.org/web/20181113035655/https://esa.un.org/unpd/wup/Archive/Files/studies/United%20Nations%20(1980)%20-%20Patterns%20of%20Urban%20and%20Rural%20Population%20Growth.pdf |date=2018-11-13 }}", Department of International Economic and Social Affairs, Population Studies No. 68; New York, United Nations, 1980; p. 15. "If the projections prove to be accurate, the next century will begin just after the world population achieves an urban majority; in 2000, the world is projected to be 51.3 per cent urban."</ref><ref>Edouart Glissant (Editor-in-Chief), UNESCO "Courier" ("[http://unesdoc.unesco.org/images/0006/000634/063438eo.pdf The Urban Explosion] {{Webarchive|url=https://web.archive.org/web/20170612024752/http://unesdoc.unesco.org/images/0006/000634/063438eo.pdf |date=12 June 2017 }}"), March 1985.</ref> and in 2007 writing that it would occur in 2008.<ref>{{cite web|url=http://www.un.org/esa/population/publications/wup2007/2007WUP_Highlights_web.pdf|title=World Urbanization Prospects: The 2007 Revision|access-date=29 June 2017|archive-date=13 August 2011|archive-url=https://web.archive.org/web/20110813042845/http://www.un.org/esa/population/publications/wup2007/2007WUP_Highlights_web.pdf}}</ref> Other researchers had also estimated that the halfway point was reached in 2007.<ref>Mike Hanlon, "[http://newatlas.com/go/7334/ World Population Becomes More Urban Than Rural] {{Webarchive|url=https://web.archive.org/web/20170628111021/http://newatlas.com/go/7334/ |date=28 June 2017 }}"; ''New Atlas'', 28 May 2007.</ref> Although the trend is undeniable, the precision of this statistic is dubious, due to reliance on national censuses and to the ambiguities of defining an area as urban.<ref name=BrennerSchmid2013 /><ref name= Hugo/>}}

[[Latin America]] is the most urban continent, with four-fifths of its population living in cities, including one-fifth of the population said to live in [[shantytown]]s ([[favela]]s, [[campamento (Chile)|poblaciones callampas]], etc.).<ref>Paulo A. Paranagua, "[https://www.theguardian.com/world/2012/sep/11/latin-america-urbanisation-city-growth Latin America struggles to cope with record urban growth] {{Webarchive|url=https://web.archive.org/web/20160517055347/http://www.theguardian.com/world/2012/sep/11/latin-america-urbanisation-city-growth |date=17 May 2016 }}" (), ''The Guardian'', 11 September 2012. Referring to [[UN-Habitat]], ''[http://www.citiesalliance.org/sites/citiesalliance.org/files/SOLAC-ProjectOutput.pdf The State of Latin American and Caribbean Cities 2012: Towards a new urban transition] {{Webarchive|url=https://web.archive.org/web/20181113035703/http://www.citiesalliance.org/sites/citiesalliance.org/files/SOLAC-ProjectOutput.pdf |date=13 November 2018 }}''; Nairobi: United Nations Human Settlements Programme, 2012.</ref> [[Batam]], [[Indonesia]], [[Mogadishu]], [[Somalia]], [[Xiamen]], [[China]], and [[Niamey]], [[Niger]], are considered among the world's fastest-growing cities, with annual growth rates of 5–8%.<ref>Helen Massy-Beresford, "[https://www.theguardian.com/cities/2015/nov/18/where-is-the-worlds-fastest-growing-city-batam-niamey-xiamen Where is the fastest growing city in the world?] {{Webarchive|url=https://web.archive.org/web/20170515225754/https://www.theguardian.com/cities/2015/nov/18/where-is-the-worlds-fastest-growing-city-batam-niamey-xiamen |date=15 May 2017 }}"; ''The Guardian'', 18 November 2015.</ref> In general, the [[developed country|more developed countries]] of the "[[Global North]]" remain more urbanized than the [[less developed countries]] of the "[[Global South]]"—but the difference continues to shrink because urbanization is happening faster in the latter group. Asia is home to by far the greatest absolute number of city-dwellers: over two billion and counting.<ref name="FreyZimmer2001" /> The UN predicts an additional 2.5 billion city dwellers (and 300 million fewer country dwellers) worldwide by 2050, with 90% of urban population expansion occurring in Asia and Africa.<ref name="SenguptaUN2014" /><ref>Mark Anderson & Achilleas Galatsidas, "[https://www.theguardian.com/global-development/2014/jul/10/urban-population-growth-africa-asia-united-nations Urban population boom poses massive challenges for Africa and Asia] {{Webarchive|url=https://web.archive.org/web/20171010005936/https://www.theguardian.com/global-development/2014/jul/10/urban-population-growth-africa-asia-united-nations |date=10 October 2017 }}" ''The Guardian'' (Development data: Datablog), 10 July 2014.</ref>

[[Megacities]], cities with populations in the multi-millions, have proliferated into the dozens, arising especially in Asia, Africa, and Latin America.<ref>Kaplan et al. (2004), p. 15. "Global cities need to be distinguished from megacities, defined here as cities with more than 8 million people. [...] Only New York and London qualified as megacities 50 years ago. By 1990, just over 10 years ago, 20 megacities existed, 15 of which were in less economically developed regions of the world. In 2000, the number of megacities had increased to 26, again all except 6 are located in the less developed world regions."</ref><ref>Frauke Kraas & Günter Mertins, "Megacities and Global Change"; in Kraas et al. (2014), p. 2. "While seven megacities (with more than five million inhabitants) existed in 1950 and 24 in 1990, by 2010 there were 55 and by 2025 there will be—according to estimations—87 megacities (UN 2012; Fig. 1). "</ref> Economic globalization fuels the growth of these cities, as new torrents of foreign [[Financial capital|capital]] arrange for rapid industrialization, as well as the [[offshoring|relocation of major businesses]] from Europe and North America, attracting [[immigrant]]s from near and far.<ref>Frauke Kraas & Günter Mertins, "Megacities and Global Change"; in Kraas et al. (2014), pp. 2–3. "Above all, globalisation processes were and are the motors that drive these enormous changes and are also the driving forces, together with transformation and liberalisation policies, behind the economic developments of the last c. 25 years (in China, especially the so-called socialism with Chinese characteristics that started under Deng Xiaoping in 1978/1979, in India essentially during the course of the economic reform policies of the so-called New Economic Policy as of 1991"; Cartier 2001; Nissel 1999). Especially in megacities, these reforms led to enormous influx of foreign direct investments, to intensive industrialization processes through international relocation of production locations and depending upon the location, partially to considerable expansion of the services sector with increasing demand for office space as well as to a reorientation of national support policies—with a not to be mistaken influence of transnationally acting conglomerates but also considerable transfer payments from overseas communities. In turn, these processes are flanked and intensified through, at times, massive migration movements of national and international migrants into the megacities (Baur et al. 2006).</ref> A deep gulf divides the rich and poor in these cities, which usually contain a super-wealthy elite living in [[gated community|gated communities]] and large masses of people living in substandard housing with inadequate infrastructure and otherwise poor conditions.<ref>Shipra Narang Suri & Günther Taube, "Governance in Megacities: Experiences, Challenges and Implications for International Cooperation"; in Kraas et al. (2014), p. 196.</ref>

Cities around the world have expanded physically as they grow in population, with increases in their surface extent, with the creation of high-rise buildings for residential and commercial use, and with development underground.<ref>{{Cite journal |last1=Graham |first1=Stephen |last2=Hewitt |first2=Lucy |date=February 2013 |title=Getting off the ground: On the politics of urban verticality |url=https://www.researchgate.net/publication/258175637 |url-status=live |journal=Progress in Human Geography|volume=37 |issue=1 |pages=72–92 |doi=10.1177/0309132512443147 |s2cid=129435992 |issn=0309-1325 |archive-url=https://web.archive.org/web/20171010004828/https://www.researchgate.net/profile/Stephen_Graham11/publication/258175637_Getting_off_the_ground_On_the_politics_of_urban_verticality/links/57cebebb08ae83b3746222d1.pdf |archive-date=2017-10-10 |via=[[ResearchGate]]}}</ref><ref>Eduardo F.J. de Mulder, Jacques Besner, & Brian Marker, "Underground Cities"; in Kraas et al. (2014), pp. 26–29.</ref>

Urbanization can create rapid demand for [[water resources management]], as formerly good sources of freshwater become overused and polluted, and the volume of [[sewage]] begins to exceed manageable levels.<ref name="Bakker2003" />

== Government ==
{{Further|Local government}}
[[File:City Council of Tehran, 17 September 2015.jpg|thumb|The city council of [[Tehran]] meets in September 2015]]
[[Local government|The local government]] of cities takes different forms including prominently the [[municipality]] (especially [[local government in England|in England]], [[local government in the United States|in the United States]], [[municipal governance in India|India]], and former [[crown colonies|British colonies]]; legally, the [[municipal corporation]];<ref>{{Cite journal |last=Williams |first=Joan |date=1985-01-01 |title=The Invention of the Municipal Corporation: A Case Study in Legal Change |url=https://repository.uclawsf.edu/faculty_scholarship/809 |url-status=live |journal=American University Law Review |volume=34 |page=369 |archive-url=https://web.archive.org/web/20171010054608/http://repository.uchastings.edu/faculty_scholarship/809/ |archive-date=2017-10-10}}</ref> ''[[municipio]]'' in [[Municipalities of Spain|Spain]] and [[Municipalities of Portugal|Portugal]], and, along with ''[[municipalidad]]'', in most former parts of the [[Spanish Empire|Spanish]] and [[Portuguese Empire|Portuguese]] empires) and the ''commune'' ([[communes in France|in France]] and [[Communes of Chile|Chile]]; or ''[[comune]]'' in Italy).

The chief official of the city is very often called the "[[mayor]]". Whatever their true degree of political authority, the mayor typically acts as the [[figurehead]] or personification of their city.<ref>{{harvnb| Latham | McCormack | McNamara | McNeill | 2009 | p=146}}: "The figurehead of city leadership is, of course, the mayor. As 'first citizen', mayors are often associated with political parties, yet many of the most successful mayors are often those whoare able to speak 'for' their city. Rudy Giuliani, for example, while pursuing a neo-liberal political agenda, was often seen as being outside the mainstream of the national Republican party. Furthermore, mayors are often crucial in articulating the interests of their cities to external agents, be they national governments or major public and private investors."</ref>

Legal conflicts and issues arise more frequently in cities than elsewhere due to the bare fact of their greater density.<ref>McQuillan (1937/1987), §1.63. "The problem of achieving equitable balance between the two freedoms is infinitely greater in urban, metropolitan and megalopolitan situations than in sparsely settled districts and rural areas. / In the latter, sheer intervening space acts as a buffer between the privacy and well-being of one resident and the potential encroachments thereon by his neighbors in the form of noise, air or water pollution, absence of sanitation, or whatever. In a congested urban situation, the individual is powerless to protect himself from the "free" (i.e., inconsiderate or invasionary) acts of others without himself being guilty of a form of encroachment."</ref> Modern city governments thoroughly [[regulation|regulate]] [[everyday life]] in many dimensions, including [[public health|public]] and personal [[health]], [[transport]], [[burial]], [[resource]] use and [[resource extraction|extraction]], [[recreation]], and the nature and use of [[building]]s. Technologies, techniques, and laws governing these areas—developed in cities—have become ubiquitous in many areas.<ref>McQuillan (1937/1987), §1.08.</ref>
Municipal officials may be appointed from a higher level of government or elected locally.<ref>McQuillan (1937/1987), §1.33.</ref>

=== Municipal services ===
[[File:Aftermath of a huge fire at Thomas McKenzie & Sons Ltd. on Pearse Street, Dublin.jpg|thumb|The [[Dublin Fire Brigade]] in Dublin, Ireland, extinguishing a severe fire at a hardware store in 1970]]
Cities typically provide [[municipal services]] such as [[education]], through [[school system]]s; [[police|policing]], through police departments; and [[firefighting]], through [[fire department]]s; as well as the city's basic infrastructure. These are provided more or less routinely, in a more or less equal fashion.<ref name="JonesEtAl1980">Bryan D. Jones, Saadia R. Greenbeg, Clifford Kaufman, & Joseph Drew, "Service Delivery Rules and the Distribution of Local Government Services: Three Detroit Bureaucracies"; in Hahn & Levine (1980). "Local government bureaucracies more or less explicitly accept the goal of implementing rational criteria for the delivery of services to citizens, even though compromises may have to be made in the establishment of these criteria. These production oriented criteria often give rise to "service deliver rules", regularized procedures for the delivery of services, which are attempts to codify the productivity goals of urban service bureaucracies. These rules have distinct, definable distributional consequences which often go unrecognized. That is, the decisions of governments to adopt rational service delivery rules can (and usually do) differentially benefit citizens."</ref><ref>Lineberry, Robert L. "Mandating Urban Equality: The Distribution of Municipal Public Services"; in Hahn & Levine (1980). See: [[Shaw, Mississippi|Hawkins v. Town of Shaw]] (1971).</ref> Responsibility for administration usually falls on the city government, but some services may be operated by a higher level of government,<ref>George Nilson, "[http://www.baltimoresun.com/news/opinion/oped/bs-ed-state-control-police-20170228-story.html Baltimore police under state control for good reason] {{Webarchive|url=https://web.archive.org/web/20171010010234/http://www.baltimoresun.com/news/opinion/oped/bs-ed-state-control-police-20170228-story.html |date=10 October 2017 }}", ''Baltimore Sun'' 28 February 2017.</ref> while others may be privately run.<ref>{{Cite journal |last1=Dilger |first1=Robert Jay |last2=Moffett |first2=Randolph R. |last3=Struyk |first3=Linda |year=1997 |title=Privatization of Municipal Services in America's Largest Cities |journal=Public Administration Review |volume=57 |issue=1 |page=21 |doi=10.2307/976688 |jstor=976688}}</ref> Armies may assume responsibility for policing cities in states of domestic turmoil such as America's [[King assassination riots]] of 1968.

=== Finance ===
The traditional basis for municipal finance is local [[property tax]] levied on [[real estate]] within the city. Local government can also collect revenue for services, or by leasing land that it owns.<ref name="Gwilliam2013" /> However, financing municipal services, as well as [[urban renewal]] and other development projects, is a perennial problem, which cities address through appeals to higher governments, arrangements with the private sector, and techniques such as [[privatization]] (selling services into the [[private sector]]), [[corporatization]] (formation of quasi-private municipally owned corporations), and [[financialization]] (packaging city assets into tradeable financial public contracts and other related rights). This situation has become acute in deindustrialized cities and in cases where businesses and wealthier citizens have moved outside of [[city limits]] and therefore beyond the reach of taxation.<ref>McQuillan (1937/1987), §§1.65–1.66.</ref><ref>David Walker, "The New System of Intergovernmental Relations: Fiscal Relief and More Governmental Intrusions"; in Hahn & Levine (1980).</ref><ref>{{Cite journal |last1=Voorn |first1=Bart |last2=van Genugten |first2=Marieke L. |last3=van Thiel |first3=Sandra |date=2017-09-03 |title=The efficiency and effectiveness of municipally owned corporations: a systematic review |journal=Local Government Studies|volume=43 |issue=5 |pages=820–841 |doi=10.1080/03003930.2017.1319360 |s2cid=157153401 |issn=0300-3930 |doi-access=free |hdl=2066/176125 |hdl-access=free }}</ref><ref name="Weber2010" /> Cities in search of [[cash and cash equivalents|ready cash]] increasingly resort to the [[municipal bond]], essentially a loan with [[Maturity (finance)|interest]] and a [[Maturity (finance)|repayment date]].<ref>{{Cite journal |last=Weber |first=Rachel |year=2002 |title=Extracting Value from the City: Neoliberalism and Urban Redevelopment |url=http://www.overgaardtonnesen.dk/TEKSTERNE/09-Weber-Extracting-Value-from-the-City.pdf |journal=[[Antipode (journal)|Antipode]]|volume=34 |issue=3 |pages=519–540 |doi=10.1111/1467-8330.00253 |bibcode=2002Antip..34..519W |issn=0066-4812 |access-date=26 September 2022 |archive-date=26 September 2022 |archive-url=https://web.archive.org/web/20220926150915/http://www.overgaardtonnesen.dk/TEKSTERNE/09-Weber-Extracting-Value-from-the-City.pdf }}</ref> City governments have also begun to use [[tax increment financing]], in which a development project is financed by loans based on future tax revenues which it is expected to yield.<ref name="Weber2010">{{Cite journal |last=Weber |first=Rachel |date=July 2010 |title=Selling City Futures: The Financialization of Urban Redevelopment Policy |url=https://onlinelibrary.wiley.com/doi/10.1111/j.1944-8287.2010.01077.x |journal=Economic Geography|volume=86 |issue=3 |pages=251–274 |doi=10.1111/j.1944-8287.2010.01077.x |s2cid=153912312 |issn=0013-0095 |quote=TIF is an increasingly popular local redevelopment policy that allows municipalities to designate a 'blighted' area for redevelopment and use the expected increase in property (and occasionally sales) taxes there to pay for initial and ongoing redevelopment expenditures, such as land acquisition, demolition, construction, and project financing. Because developers require cash up-front, cities transform promises of future tax revenues into securities that far-flung buyers and sellers exchange through local markets.|url-access=subscription }}</ref> Under these circumstances, creditors and consequently city governments place a high importance on city [[credit rating]]s.<ref>{{Cite journal |last=Pacewicz |first=Josh |date=2013-07-01 |title=Tax increment financing, economic development professionals and the financialization of urban politics |url=https://academic.oup.com/ser/article-lookup/doi/10.1093/ser/mws019 |journal=Socio-Economic Review|volume=11 |issue=3 |pages=413–440 |doi=10.1093/ser/mws019 |issn=1475-1461 |quote=A city's credit rating not only influences its ability to sell bonds, but has become a general signal of fiscal health. Detroit's partial recovery in the early 1990s, for example, was reversed when Moody's downgraded the rating of the city's general obligation bonds, precipitating new rounds of capital flight (Hackworth, 2007). The need to maintain a high credit rating constrains municipal actors by making it difficult to finance discretionary projects in traditional ways.|url-access=subscription }}</ref>

=== Governance ===
[[File:Ripon Building panorama.jpg|thumb|The [[Ripon Building]], the headquarters of [[Greater Chennai Corporation]] in Chennai, is one of the oldest city governing corporations in [[Asia]]. ]]
[[Governance]] includes government but refers to a wider domain of [[social control]] functions implemented by many actors including [[non-governmental organization]]s.<ref>Gupta et al. (2015), pp. 4, 29. "We thereby understand urban governance as the multiple ways through which city governments, businesses and residents interact in managing their urban space and life, nested within the context of other government levels and actors who are managing their space, resulting in a variety of urban governance configurations (Peyroux et al. 2014)."</ref> The impact of globalization and the role of [[multinational corporation]]s in local governments worldwide have led to a shift in perspective on urban governance, away from the "urban regime theory" in which a coalition of local interests functionally govern, toward a theory of outside economic control, widely associated in academics with the philosophy of [[neoliberalism]].{{sfn | Latham | McCormack | McNamara | McNeill | 2009 | pp=142–143}} In the neoliberal model of governance, public utilities are [[privatization|privatized]], the industry is [[deregulation|deregulated]], and [[corporation]]s gain the status of governing actors—as indicated by the power they wield in [[public-private partnerships]] and over [[business improvement districts]], and in the expectation of self-regulation through [[corporate social responsibility]]. The biggest [[investor]]s and [[real estate developer]]s act as the city's [[de facto]] urban planners.<ref>Gupta, Verrest, and Jaffe, "Theorizing Governance", in Gupta et al. (2015), pp. 30–31.</ref>

The related concept of [[good governance]] places more emphasis on the state, with the purpose of assessing urban governments for their suitability for [[development assistance]].<ref name="Gupta2015p33">Gupta, Verrest, and Jaffe, "Theorizing Governance", in Gupta et al. (2015), pp. 31–33. "The concept of good governance itself was developed in the 1980s, primarily to guide donors in development aid (Doonbos 2001:93). It has been used both as a condition for aid and a development goal in its own right. Key terms in definitions of good governance include participation, accountability, transparency, equity, efficiency, effectiveness, responsiveness, and rule of law (e.g. Ginther and de Waart 1995; UNDP 1997; Woods 1999; Weiss 2000). [...] At the urban level, this normative model has been articulated through the idea of good urban governance, promoted by agencies such as UN Habitat. The Colombian city of Bogotá has sometimes been presented as a model city, given its rapid improvements in fiscal responsibility, provision of public services and infrastructure, public behavior, honesty of the administration, and civic pride."</ref> The concepts of governance and good governance are especially invoked in emergent megacities, where international organizations consider existing governments inadequate for their large populations.<ref>Shipra Narang Suri & Günther Taube, "Governance in Megacities: Experiences, Challenges and Implications for International Cooperation"; in Kraas et al. (2014), pp. 197–198.</ref>

=== Urban planning ===
{{Main|Urban planning|Urban design}}

[[File:La Plata desde el aire.JPG|thumb|[[La Plata]] in Argentina is based on a perfect square with 5196-meter sides, and was designed in the 1880s as the new capital of [[Buenos Aires Province]].<ref>Alain Garnier, "[https://www.epfl.ch/labs/lasur/wp-content/uploads/2018/05/GARNIER.pdf La Plata: la visionnaire trahie] {{Webarchive|url=https://web.archive.org/web/20210416094508/https://www.epfl.ch/labs/lasur/wp-content/uploads/2018/05/GARNIER.pdf |date=16 April 2021 }}"; ''Architecture & Comportment'' 4(1), 1988, pp. 59–79.</ref>]]
[[Urban planning]], the application of forethought to city design, involves optimizing land use, transportation, utilities, and other basic systems in order to achieve [[Technical aspects of urban planning|certain objectives]]. Urban planners and scholars have proposed overlapping [[theories of urban planning|theories]] as ideals of how plans should be formed. Planning tools, beyond the original design of the city itself, include [[public capital]] investment in infrastructure and [[Land-use planning|land-use controls]] such as [[zoning]]. The continuous process of [[comprehensive planning]] involves identifying general objectives as well as collecting data to evaluate progress and inform future decisions.<ref>Levy (2017), pp. 193–235.</ref><ref name="McQuillin1987planning" />

Government is legally the final authority on planning but in practice, the process involves both public and private elements. The legal principle of [[eminent domain]] is used by the government to divest citizens of their property in cases where its use is required for a project.<ref name="McQuillin1987planning">McQuillin (1937/1987), §§1.75–179. "Zoning, a relatively recent development in the administration of local governmental units, concerns itself with the control of the use of land and structures, the size of buildings, and the use-intensity of building sites. Zoning being an exercise of the police power, it must be justified by such considerations as the protection of public health and safety, the preservation of taxable property values, and the enhancement of community welfare. [...] Municipal powers to implement and effectuate city plans are usually ample. Among these is the power of eminent domain, which has been used effectively in connection with slum clearance and the rehabilitation of blighted areas. Also available to cities in their implementation of planning objectives are municipal powers of zoning, subdivision control and the regulation of building, housing and sanitation principles."</ref> Planning often involves tradeoffs—decisions in which some stand to gain and some to lose—and thus is closely connected to the prevailing political situation.<ref>Levy (2017), p. 10. "Planning is a highly political activity. It is immersed in politics and inseparable from the law. [...] Planning decisions often involve large sums of money, both public and private. Even when little public expenditure is involved, planning decisions can deliver large benefits to some and large losses at others."</ref>

The [[history of urban planning]] dates back to some of the earliest known cities, especially in the Indus Valley and Mesoamerican civilizations, which built their cities on grids and apparently zoned different areas for different purposes.<ref name= Smith/><ref>Jorge Hardoy, ''Urban Planning in Pre-Columbian America''; New York: George Braziller, 1968.</ref> The effects of planning, ubiquitous in today's world, can be seen most clearly in the layout of [[planned community|planned communities]], fully designed prior to construction, often with consideration for interlocking physical, economic, and cultural systems.

== Society ==
=== Social structure ===
[[Urban sociology|Urban society]] is typically [[social stratification|stratified]]. Spatially, cities are formally or informally [[Geographical segregation|segregated]] along ethnic, economic, and racial lines. People living relatively close together may live, work, and play in separate areas, and associate with different people, forming [[ethnic enclave|ethnic]] or [[lifestyle enclave|lifestyle]] enclaves or, in areas of concentrated poverty, [[ghetto]]es. While in the US and elsewhere poverty became associated with the [[inner city]], in France it has become associated with the ''[[banlieue]]s'', areas of urban development that surround the city proper. Meanwhile, across Europe and North America, the racially [[white people|white]] majority is empirically the most segregated group. [[Suburb]]s in the West, and, increasingly, [[Gated community|gated communities]] and other forms of "privatopia" around the world, allow local elites to self-segregate into secure and exclusive [[neighborhood]]s.{{sfn | Latham | McCormack | McNamara | McNeill | 2009 | pp=131–140}}

Landless urban workers, contrasted with [[peasant]]s and known as the [[proletariat]], form a growing stratum of society in the age of urbanization. In [[Marxism|Marxist]] doctrine, the proletariat will inevitably [[proletarian revolution|revolt]] against the [[bourgeoisie]] as their ranks swell with disenfranchised and disaffected people lacking all stake{{clarify|date=May 2022|reason=Unusual wording – is it supposed to be "any stake" perhaps?}} in the [[status quo]].<ref>{{cite book |author1=[[Karl Marx]] |author2=[[Frederick Engels]] |title=Manifesto of the Communist Party|url=https://www.marxists.org/archive/marx/works/1848/communist-manifesto/ |archive-url=https://web.archive.org/web/20180724053228/https://www.marxists.org/archive/marx/works/1848/communist-manifesto/ |archive-date=24 July 2018 |date=February 1848 |language= German |translator=Samuel Moore |quote=But with the development of industry, the proletariat not only increases in number; it becomes concentrated in greater masses, its strength grows, and it feels that strength more. The various interests and conditions of life within the ranks of the proletariat are more and more equalised, in proportion as machinery obliterates all distinctions of labour, and nearly everywhere reduces wages to the same low level.}}</ref> The global urban proletariat of today, however, generally lacks the status of factory workers which in the nineteenth century provided access to the [[means of production]].<ref name="Davis2004">{{cite journal | last=Davis | first=Mike | title=The Urbanization of Empire: Megacities and the Laws of Chaos | journal=Social Text | publisher=Duke University Press | volume=22 | issue=4 | date=2005-01-18 | issn=1527-1951 | pages=9–15 | doi=10.1215/01642472-22-4_81-9 | url=https://muse.jhu.edu/pub/4/article/177068/summary |quote= "Although studies of the so-called urban informal economy have shown myriad secret liaisons with outsourced multinational production systems, the larger fact is that hundreds of millions of new urbanites must further subdivide the peripheral economic niches of personal service, casual labor, street vending, rag picking, begging, and crime. <br /> This outcast proletariat—perhaps 1.5 billion people today, 2.5 billion by 2030—is the fastest-growing and most novel social class on the planet. By and large, the urban informal working class is not a labor reserve army in the nineteenth-century sense: a backlog of strikebreakers during booms; to be expelled during busts; then reabsorbed again in the next expansion. On the contrary, this is a mass of humanity structurally and biologically redundant to the global accumulation and the corporate matrix.<br /> It is ontologically both similar and dissimilar to the historical agency described in the ''Communist Manifesto''. Like the traditional working classes, it has radical chains in the sense of having little vested interest in the reproduction of private property. But it is not a socialized collectivity of labor and it lacks significant power to disrupt or seize the means of production. It does possess, however, yet unmeasured powers of subverting urban order."| url-access=subscription }}</ref>

=== Economics ===
[[File:Taipei Skyline 2022.06.29.jpg|thumb|Clusters of skyscrapers in [[Xinyi Planning District]], the centre of commerce and finance of [[Taipei]], the capital of [[Taiwan]]]]
Historically, cities rely on [[rural area]]s for [[intensive farming]] to [[crop yield|yield surplus crops]], in exchange for which they provide money, political administration, manufactured goods, and culture.<ref name= Kaplan155/><ref name= Marshall/> [[Urban economics]] tends to analyze larger agglomerations, stretching beyond city limits, in order to reach a more complete understanding of the local [[labor market]].<ref>Marshall (1989), pp. 5–6.</ref>

As hubs of trade, cities have long been home to [[retail]] commerce and [[Consumption (economics)|consumption]] through the interface of [[shopping]]. In the 20th century, [[department store]]s using new techniques of [[advertising]], [[public relations]], [[decorative arts|decoration]], and [[design]], transformed urban shopping areas into [[fantasy world]]s encouraging self-expression and escape through [[consumerism]].<ref>{{harvnb| Latham | McCormack | McNamara | McNeill | 2009 | pp=160–164}}: "Indeed, the design of the buildings often revolves around the consumable fantasy experience, seen most markedly in the likes of Universal CityWalk, Disneyland and Las Vegas. Architecture critic Ada Louise Huxtable (1997) names architectural structures built specifically as entertainment spaces as 'Architainment'. These places are, of course, places to make money, but they are also stages of performance for an interactive consumer."</ref><ref>Leach (1993), pp. 173–176 and passim.</ref>

In general, the density of cities expedites commerce and facilitates [[knowledge spillover]]s, helping people and firms exchange information and generate new ideas.<ref>{{cite web |url=http://www.philadelphiafed.org/files/br/brq401gc.pdf |title=Knowledge Spillovers |access-date=16 May 2010 |archive-date=1 May 2014 |archive-url=https://web.archive.org/web/20140501140511/http://www.philadelphiafed.org/files/br/brq401gc.pdf }}</ref><ref>{{Cite journal |last1=Calder |first1=Kent E. |last2=de Freytas |first2=Mariko |year=2009 |title=Global Political Cities as Actors in Twenty-First Century International Affairs |url=https://muse.jhu.edu/article/269254 |journal=SAIS Review of International Affairs|volume=29 |issue=1 |pages=79–96 |doi=10.1353/sais.0.0036 |s2cid=154230409 |issn=1945-4724 |quote=Beneath state-to-state dealings, a flurry of activity occurs, with interpersonal networks forming policy communities involving embassies, think tanks, academic institutions, lobbying firms, politicians, congressional staff, research centers, NGOs, and intelligence agencies. This interaction at the level of 'technostructure'—heavily oriented toward information gathering and incremental policy modification—is too complex and voluminous to be monitored by top leadership, yet nevertheless often has important implications for policy.|url-access=subscription }}</ref> A thicker labor market allows for better skill matching between firms and individuals. Population density also enables sharing of common infrastructure and production facilities; however, in very dense cities, increased crowding and waiting times may lead to some negative effects.<ref>{{cite journal| last1 = Borowiecki| first1 = Karol J.| title = Agglomeration Economies in Classical Music| journal = Papers in Regional Science| volume = 94| issue = 3| pages = 443–468| year = 2015| url = https://ideas.repec.org/p/cue/wpaper/awp-02-2013.html| doi = 10.1111/pirs.12078| bibcode = 2015PRegS..94..443B| hdl = 10419/246978| access-date = 11 November 2015| archive-date = 4 March 2016| archive-url = https://web.archive.org/web/20160304201317/https://ideas.repec.org/p/cue/wpaper/awp-02-2013.html| url-status = live| hdl-access = free}}</ref>

Although [[manufacturing]] fueled the growth of cities, many now rely on a [[Tertiary sector of the economy|tertiary]] or [[service economy]]. The services in question range from [[tourism]], [[hospitality industry|hospitality]], [[entertainment]], and [[housekeeping]] to [[grey-collar]] work in [[legal outsourcing|law]], financial consulting, and [[management|administration]].<ref name= Kaplan164/><ref>[[Saskia Sassen]], "[https://www.researchgate.net/profile/Saskia_Sassen/publication/246326854_Global_Cities_and_Survival_Circuits/links/5411771c0cf29e4a2329630c.pdf Global Cities and Survival Circuits] {{Webarchive|url=https://web.archive.org/web/20171010004747/https://www.researchgate.net/profile/Saskia_Sassen/publication/246326854_Global_Cities_and_Survival_Circuits/links/5411771c0cf29e4a2329630c.pdf |date=10 October 2017 }}"; in ''Global Woman: Nannies, Maids, and Sex Workers in the New Economy'' ed. [[Barbara Ehrenreich]] and [[Arlie Russell Hochschild]]; New York: Henry Holt and Company, 2002.</ref>

According to a scientific model of cities by Professor [[Geoffrey West]], with the doubling of a city's size, salaries per capita will generally increase by 15%.<ref>{{Cite journal
| last1 = Bettencourt | first1 = L. M. A.
| last2 = Lobo | first2 = J.
| last3 = Helbing | first3 = D.
| last4 = Kuhnert | first4 = C.
| last5 = West | first5 = G. B.
| author-link5 = Geoffrey West
| title = Growth, innovation, scaling, and the pace of life in cities
| doi = 10.1073/pnas.0610172104
| journal = Proceedings of the National Academy of Sciences
| volume = 104
| issue = 17
| pages = 7301–7306
| year = 2007
| pmid = 17438298
| pmc =1852329
|bibcode = 2007PNAS..104.7301B | doi-access = free
}}</ref>

=== Culture and communications ===
[[File:Paris - Eiffelturm und Marsfeld2.jpg|thumb|[[Paris]] is one of the best-known cities in the world.<ref>{{cite book|first=Emma|last=Nathan|title=Cities: Eye Openers|year=2002|page=2|isbn=978-1-56711-596-3|publisher=[[Blackbirch Press]]}}</ref>]]
[[File:Nepalese Dancers at Heritage Days, Edmonton.jpg|thumb|[[Nepal]]ese dancers at [[Edmonton Heritage Festival]], in [[Alberta]], Canada, an example of the cultural diversity of a city]]
Cities are typically hubs for [[education]] and [[the arts]], supporting [[university|universities]], [[museum]]s, [[temple]]s, and other [[cultural institutions]].<ref name="Marshall14">Marshall (1989), pp. 14–15.</ref> They feature impressive displays of [[architecture]] ranging from small to enormous and ornate to [[Brutalist architecture|brutal]]; [[skyscraper]]s, providing thousands of offices or homes within a small footprint, and visible from miles away, have become iconic urban features.{{sfn | Latham | McCormack | McNamara | McNeill | 2009 | pp=84–85}} Cultural elites tend to live in cities, bound together by shared [[cultural capital]], and themselves play some role in governance.<ref>{{Cite journal |last=Zheng |first=Jane |date=2017-05-19 |title=Toward a new concept of the 'cultural elite state': Cultural capital and the urban sculpture planning authority in elite coalition in Shanghai |url=https://www.tandfonline.com/doi/full/10.1080/07352166.2016.1255531 |journal=Journal of Urban Affairs|volume=39 |issue=4 |pages=506–527 |doi=10.1080/07352166.2016.1255531 |s2cid=149125180 |issn=0735-2166|url-access=subscription }}</ref> By virtue of their status as centers of culture and literacy, cities can be described as the locus of [[civilization]], [[human history]], and [[social change]].<ref>McQuillan (1937/1987), §§1.04–1.05. "Almost by definition, cities have always provided the setting for great events and have been the focal points for social change and human development. All great cultures have been city-born. World history is basically the history of city dwellers."</ref><ref>{{Cite journal |last1=Redfield |first1=Robert |last2=Singer |first2=Milton B. |year=1954 |title=The Cultural Role of Cities |url=https://archive.org/details/sim_economic-development-and-cultural-change_1954-10_3_1/page/52 |journal=Economic Development and Cultural Change |volume=3 |issue=1 |pages=53–73 |doi=10.1086/449678 |issn=0013-0079 |jstor=1151661 |s2cid=154664764 }}</ref>

Density makes for effective [[mass communication]] and transmission of [[news]], through [[herald]]s, printed [[proclamation]]s, [[newspaper]]s, and digital media. These communication networks, though still using cities as hubs, penetrate extensively into all populated areas. In the age of rapid communication and transportation, commentators have described urban culture as nearly ubiquitous<ref name=HugoEtAl2003>Graeme Hugo, Anthony Champion, & Alfredo Lattes, "[https://www.jstor.org/stable/3115228 Toward a New Conceptualization of Settlements for Demography] {{Webarchive|url=https://web.archive.org/web/20200729082041/https://www.jstor.org/stable/3115228 |date=29 July 2020 }}", ''Population and Development Review'' 29(2), June 2003.</ref><ref>Magnusson (2011), p. 21. "These statistics probably underestimate the degree to which the world has been urbanized, since they obscure the fact that rural areas have become so much more urban as a result of modern transportation and communication. A farmer in Europe or California who checks the markets every morning on the computer, negotiates with product brokers in distant cities, buys food at a supermarket, watches television every night, and takes vacations half a continent away is not exactly living a traditional rural life. In most respects such a farmer is an urbanite living in the countryside, albeit an urbanite who has many good reasons for perceiving himself or herself as a rural person."</ref><ref>Mumford (1961), pp. 563–567. "Many of the original functions of the city, once natural monopolies, demanding the physical presence of all participants, have now been transposed into forms capable of swift transportation, mechanical manifolding, electronic transmission, worldwide distribution."</ref> or as no longer meaningful.<ref>{{Cite book |last1=Theall |first1=Donald F. |title=The virtual Marshall McLuhan |last2=Carpenter |first2=Edmund |date=2001 |publisher=McGill-Queen's Univ. Press |isbn=978-0-7735-2119-3 |location=Montreal}}</ref>

Today, a city's promotion of its cultural activities dovetails with [[place branding]] and [[city marketing]], [[public diplomacy]] techniques used to inform development strategy; attract businesses, investors, residents, and tourists; and create [[collective identity|shared identity]] and [[sense of place]] within the metropolitan area.<ref>Ashworth, Kavaratzis, & Warnaby, "The Need to Rethink Place Branding"; in Kavaratzis, Warnaby, & Ashworth (2015), p. 15.</ref><ref name=Wachsmuth2014 /><ref>Adriana Campelo, "Rethinking Sense of Place: Sense of One and Sense of Many"; in Kavaratzis, Warnaby, & Ashworth (2015).</ref><ref name=KerrOliver2015>Greg Kerr & Jessica Oliver, "Rethinking Place Identities", in Kavaratzis, Warnaby, & Ashworth (2015).</ref> Physical inscriptions, [[Historical marker|plaques]], and [[monument]]s on display physically transmit a historical context for urban places.{{sfn | Latham | McCormack | McNamara | McNeill | 2009 | p=186–189}} Some cities, such as [[Jerusalem]], [[Mecca]], and [[Rome]] have indelible religious status and for hundreds of years have attracted [[pilgrim]]s. Patriotic tourists visit [[Agra]] to see the [[Taj Mahal]], or [[New York City]] to visit the [[World Trade Center (2001–present)|World Trade Center]]. [[Elvis]] lovers visit [[Memphis, Tennessee|Memphis]] to pay their respects at [[Graceland]].{{sfn | Latham | McCormack | McNamara | McNeill | 2009 | pp=41, 189–192}} Place brands (which include place satisfaction and place loyalty) have great economic value (comparable to the value of commodity [[brand]]s) because of their influence on the [[decision-making]] process of people thinking about doing business in—"purchasing" (the brand of)—a city.<ref name=KerrOliver2015 />

[[Bread and circuses]] among other forms of cultural appeal, attract and entertain [[commoner|the masses]].<ref name=MoholyNagy1968p136>Moholy-Nagy (1968), pp. 136–137. "Why do anonymous people—the poor, the underprivileged, the unconnected—frequently prefer life under miserable conditions in tenements to the healthy order and tranquility of small towns or the sanitary subdivisions of semirural developments? The imperial planners and architects knew the answer, which is as valid today as it was 2,000 years ago. Big cities were created as power images of a competitive society, conscious of its achievement potential. Those who came to live in them did so in order to participate and compete on any attainable level. Their aim was to share in public life, and they were willing to pay for this share with personal discomfort. 'Bread and games' was a cry for opportunity and entertainment still ranking foremost among urban objectives."</ref><ref>Fred Coalter, "[http://storre.stir.ac.uk/handle/1893/1742 The FIFA World Cup and Social Cohesion: Bread and Circuses or Bread and Butter?] {{Webarchive|url=https://web.archive.org/web/20171010005333/http://storre.stir.ac.uk/handle/1893/1742 |date=10 October 2017 }}"; International Council of Sport Science and Physical Education ''Bulletin'' [http://www.icsspe.org/content/no-53-cd-rom 53] {{Webarchive|url=https://web.archive.org/web/20170706111108/http://www.icsspe.org/content/no-53-cd-rom |date=6 July 2017 }}, May 2008 (Feature: Feature: "Mega Sport Events in Developing Countries").</ref> Sports also play a major role in city branding and local [[Identity (social science)|identity]] formation.<ref>{{Cite journal |last=Schimmel |first=Kimberly S. |year=2015 |title=Assessing the sociology of sport: On sport and the city |url=http://journals.sagepub.com/doi/10.1177/1012690214539484 |journal=International Review for the Sociology of Sport|volume=50 |issue=4–5 |pages=591–595 |doi=10.1177/1012690214539484 |s2cid=142777232 |issn=1012-6902|url-access=subscription }}</ref> Cities go to considerable lengths in competing to host the [[Olympic Games]], which bring global attention and tourism.<ref name=Ward2008>Stephen V. Ward, "Promoting the Olympic City"; in John R. Gold & Margaret M. Gold, eds., ''Olympic Cities: City Agendas, Planning and the World's Games'', 1896–2016; London & New York: Routledge (Taylor & Francis), 2008/2011; {{ISBN|978-0-203-84074-0}}. "All this media exposure, provided it is reasonably positive, influences many tourist decisions at the time of the Games. This tourism impact will focus on, but extend beyond, the city to the country and the wider global region. More importantly, there is also huge long term potential for both tourism and investment (Kasimati, 2003). <br /> No other city marketing opportunity achieves this global exposure. At the same time, provided it is carefully managed at the local level, it also gives a tremendous opportunity to heighten and mobilize the commitment of citizens to their own city. The competitive nature of sport and its unrivalled capacity to be enjoyed as a mass cultural activity gives it many advantages from the marketing point of view (S.V. Ward, 1998, pp. 231–232). In a more subtle way it also becomes a metaphor for the notion of cities having to compete in a global marketplace, a way of reconciling citizens and local institutions to the wider economic realities of the world."</ref> Paris, a city known for its cultural history, was the site of the most recent Olympics in the summer of 2024.<ref>{{Cite news |date=2023-01-25 |title=Olympics: Paris rushing to complete construction work by 2024. |work=Real Estate Monitor Worldwide |publisher=SyndiGate Media Inc. |url=https://link.gale.com/apps/doc/A734480538/ITOF?u=anon~a4ae51c2&sid=bookmark-ITOF&xid=73cfb234 |via=Gale General OneFile}}</ref>

=== Warfare ===
[[File:The Second World War 1939-45- Victory and Aftermath IND5196.jpg|thumb|The [[Atomic bombings of Hiroshima and Nagasaki|atomic bombing]] of [[Hiroshima]] on 6 August 1945 devastated the city and led to [[Japanese Instrument of Surrender|Imperial Japan's surrender]] and the end of [[World War II]].]]
Cities play a crucial strategic role in warfare due to their economic, demographic, symbolic, and political centrality. For the same reasons, they are targets in [[asymmetric warfare]]. Many cities throughout history were founded under military auspices, a great many have incorporated [[fortification]]s, and military principles continue to [[military urbanism|influence urban design]].{{sfn | Latham | McCormack | McNamara | McNeill | 2009 | pp=127–128}} Indeed, war may have served as the social rationale and economic basis for the very earliest cities.<ref name=Mumfurd1961war>Mumford (1961), pp. 39–46. "As the physical means increased, this one-sided power mythology, sterile, indeed hostile to life, pushed its way into every corner of the urban scene and found, in the ''new'' institution of organized war, its completest expression. [...] Thus both the physical form and the institutional life of the city, from the very beginning to the urban implosion, were shaped in no small measure by the irrational and magical purposes of war. From this source sprang the elaborate system of fortifications, with walls, ramparts, towers, canals, ditches, that continued to characterize the chief historic cities, apart from certain special cases—as during the Pax Romana—down to the eighteenth century. [...] War brought concentration of social leadership and political power in the hands of a weapons-bearing minority, abetted by a priesthood exercising sacred powers and possessing secret but valuable scientific and magical knowledge."</ref><ref name=Ashworth1991p12 />

Powers engaged in [[geopolitics|geopolitical]] conflict have established fortified settlements as part of military strategies, as in the case of [[garrison]] towns, America's [[Strategic Hamlet Program]] during the [[Vietnam War]], and [[Israeli settlement]]s in Palestine.<ref>Ashworth (1991). "In more recent years, planned networks of defended settlements as part of military strategies can be found in the pacification programmes of what has become the conventional wisdom of anti-insurgency operations. Connected networks of protected settlements are inserted as islands of government control into insurgent areas—either defensively to separate existing populations from insurgents or aggressively as a means of extending control over areas—as used by the British in South Africa (1899–1902) and Malaya (1950–3) and by the Americans in Cuba (1898) and Vietnam (1965–75). These were generally small settlements and intended as much for local security as offensive operations. / The planned settlement policy of the State of Israel, however, has been both more comprehensive and has longer-term objectives. [...] These settlements provide a source of armed manpower, a defence in depth of a vulnerable frontier area and islands of cultural and political control in the midst of a potentially hostile population, thus continuing a tradition of the use of such settlements as part of similar policies in that area which is over 2,000 years old."</ref> While [[Philippine–American War|occupying]] the [[Philippines]], the US Army ordered local people to concentrate in cities and towns, in order to isolate committed insurgents and battle freely against them in the countryside.<ref>See Brigadier General [[J. Franklin Bell]]'s telegraphic circular to all station commanders, 8 December 1901, in Robert D. Ramsey III, ''[http://usacac.army.mil/cac2/cgsc/carl/download/csipubs/ramseyop25.pdf A Masterpiece of Counterguerrilla Warfare: BG J. Franklin Bell in the Philippines, 1901–1902] {{Webarchive|url=https://web.archive.org/web/20170216151944/http://usacac.army.mil/cac2/cgsc/carl/download/csipubs/ramseyop25.pdf |date=16 February 2017 }}'', Long War Series, Occasion Paper 25; Fort Leavenworth, Kansas: Combat Studies Institute Press, US Army Combined Arms Center; pp. 45–46. "Commanding officers will also see that orders are at once given and distributed to all the inhabitants within the jurisdiction of towns over which they exercise supervision, informing them of the danger of remaining outside of these limits and that unless they move by December 25th from outlying barrios and districts with all their movable food supplies, including rice, palay, chickens, live stock, etc., to within the limits of the zone established at their own or nearest town, their property (found outside of said zone at said date) will become liable to confiscation or destruction."</ref><ref>Maj. Eric Weyenberg, U.S. Army, ''[http://www.dtic.mil/docs/citations/AD1001905 Population Isolation in the Philippine War: A Case Study] {{Webarchive|url=https://web.archive.org/web/20170608222231/http://www.dtic.mil/docs/citations/AD1001905 |date=8 June 2017 }}''; School of Advanced Military Studies, United States Army Command and General Staff College, Fort Leavenworth, Kansas; January 2015.</ref>

During [[World War II]], national governments on occasion declared certain cities [[open city|open]], effectively [[surrender (military)|surrendering]] them to an advancing enemy in order to avoid damage and bloodshed. Urban warfare proved decisive, however, in the [[Battle of Stalingrad]], where Soviet forces repulsed German occupiers, with extreme casualties and destruction. In an era of [[low-intensity conflict]] and rapid urbanization, cities have become sites of long-term conflict waged both by foreign occupiers and by local governments against [[insurgency]].<ref name=Davis2004 /><ref>Ashworth (1991), p. 3. Citing L.C. Peltier and G.E. Pearcy, ''Military Geography'' (1966).</ref> Such warfare, known as [[counterinsurgency]], involves techniques of surveillance and [[psychological warfare]] as well as [[close combat]],<ref>R.D. McLaurin & R. Miller. ''[http://www.dtic.mil/get-tr-doc/pdf?AD=ADA219359 Urban Counterinsurgency: Case Studies and Implications for U.S. Military Forces] {{Webarchive|url=https://web.archive.org/web/20170629092550/http://www.dtic.mil/get-tr-doc/pdf?AD=ADA219359 |date=29 June 2017 }}''. Springfield, VA: Abbott Associates, October 1989. Produced for U.S. Army Human Engineering Laboratory at [[Aberdeen Proving Ground]].</ref> and functionally extends modern urban [[crime prevention]], which already uses concepts such as [[defensible space theory|defensible space]].<ref>Ashworth (1991), pp. 91–93. "However, some specific sorts of crime, together with those antisocial activities which may or may not be treated as crime (such as vandalism, graffiti daubing, littering and even noisy or boisterous behavior), do play various roles in the process of insurgency. This leads in consequence to defensive reactions on the part of those responsible for public security, and by individual citizens concerned for their personal safety. The authorities react with situational crime prevention as part of the armoury of urban defense, and individuals fashion their behavior according to an 'urban geography of fear'."</ref>

Although capture is the more common objective, warfare has in some cases spelled complete destruction for a city. Mesopotamian [[Cuneiform script#List of major cuneiform tablet discoveries|tablets]] and [[ruins]] attest to such destruction,<ref>Adams (1981), p. 132 "Physical destruction and ensuing decline of population were certain to be particularly severe in the case of cities that joined unsuccessful rebellions, or whose ruling dynasts were overcome by others in abbtle. The traditional lamentations provide eloquently stylized literary accounts of this, while in other cases the combinations of archaeological evidence with the testimony of a city's like Ur's victorious opponent as to its destruction grounds the world of metaphor in harsh reality (Brinkman 1969, pp. 311–312)."</ref> as does the Latin motto ''[[Carthago delenda est]]''.<ref>Fabien Limonier, "[http://www.persee.fr/doc/rea_0035-2004_1999_num_101_3_4773 Rome et la destruction de Carthage: un crime gratuit?] {{Webarchive|url=https://web.archive.org/web/20180602133751/https://www.persee.fr/doc/rea_0035-2004_1999_num_101_3_4773 |date=2 June 2018 }}" ''Revue des Études Anciennes'' 101(3).</ref><ref>{{Cite journal |last=Kiernan |first=Ben |date=August 2004 |title=The First Genocide: Carthage, 146 BC |url=https://gsp.yale.edu/sites/default/files/first_genocide.pdf |url-status=live |journal=Diogenes|volume=51 |issue=3 |pages=27–39 |doi=10.1177/0392192104043648 |s2cid=143199778 |issn=0392-1921 |archive-url=https://web.archive.org/web/20170516201720/http://gsp.yale.edu/sites/default/files/first_genocide.pdf |archive-date=2017-05-16}}</ref> Since the [[atomic bombings of Hiroshima and Nagasaki]] and throughout the [[Cold War]], [[Nuclear strategy|nuclear strategists]] continued to contemplate the use of "[[countervalue|counter-value]]" targeting: crippling an enemy by annihilating its valuable cities, rather than [[counterforce|aiming primarily at its military forces]].<ref>{{Cite journal |last=Westou |first=Burns H. |title=Nuclear Weapons versus International Law: A Contextual Reassessment |url=http://lawjournal.mcgill.ca/userfiles/other/7673710-westou.pdf |journal=McGill Law Journal |volume=28 |page=577 |archive-url=https://web.archive.org/web/20171010010611/http://lawjournal.mcgill.ca/userfiles/other/7673710-westou.pdf |archive-date=2017-10-10 |quote=As noted above, nuclear weapons designed for countervalue or city-killing purposes tend to be of the strategic class, with known yields of deployed warheads averaging somewhere between two and three times and 1500 times the firepower of the bombs dropped on Hiroshima and Nagasaki.}}</ref><ref>Dallas Boyd, "[http://www.au.af.mil/au/ssq/digital/pdf/Spring16/Boyd.pdf Revealed Preference and the Minimum Requirements of Nuclear Deterrence] {{Webarchive|url=https://web.archive.org/web/20170131081833/http://www.au.af.mil/au/ssq/digital/pdf/Spring16/Boyd.pdf |date=2017-01-31 }}"; ''Strategic Studies Quarterly'', Spring 2016.</ref>

=== Climate change ===
{{main|Climate change and cities}}

{{Excerpt|Climate change and cities}}

== Infrastructure ==
[[File:Traffic_congestion_Jl_Asia_Afrika_Bandung.jpg|thumb|Traffic congestion in [[Bandung]] in Indonesia]]
Urban [[infrastructure]] involves various physical networks and spaces necessary for transportation, water use, energy, recreation, and public functions.<ref name=Tarr>[[Joel A. Tarr]], "The Evolution of the Urban Infrastructure in the Nineteenth and Twentieth Centuries"; in Hanson (1984).</ref> Infrastructure carries a high initial cost in [[fixed capital]] but lower [[marginal cost]]s and thus positive [[economies of scale]].<ref name=WellmanSpiller2012>Wellman & Spiller, "Introduction", in Wellman & Spiller (2012).</ref> Because of the higher [[barriers to entry]], these networks have been classified as [[natural monopoly|natural monopolies]], meaning that economic logic favors control of each network by a single organization, public or private.<ref name=Bakker2003 /><ref name=WellmanPretorius2012 />

Infrastructure in general plays a vital role in a city's capacity for economic activity and expansion, underpinning the very survival of the city's inhabitants, as well as technological, commercial, industrial, and social activities.<ref name=Tarr /><ref name=WellmanSpiller2012 /> Structurally, many infrastructure systems take the form of [[network theory|networks]] with redundant links and multiple pathways, so that the system as a whole continues to operate even if parts of it fail.<ref name=WellmanPretorius2012>Kath Wellman & Frederik Pretorius, "Urban Infrastructure: Productivity, Project Evaluation, and Finance"; in Wellman & Spiller (2012).</ref> The particulars of a city's infrastructure systems have historical [[path dependence]] because new development must build from what exists already.<ref name=WellmanSpiller2012 />

[[Megaproject]]s such as the construction of [[airport]]s, [[power plant]]s, and [[railway]]s require large upfront investments and thus tend to require funding from the national government or the private sector.{{sfn | Latham | McCormack | McNamara | McNeill | 2009 | p=70}}<ref name=WellmanPretorius2012 /> Privatization may also extend to all levels of infrastructure construction and maintenance.<ref>Kath Wellman & Frederik Pretorius, "Urban Infrastructure: Productivity, Project Evaluation, and Finance"; in Wellman & Spiller (2012), pp. 73–74. "The NCP established a legislative regime at Federal and State levels to facilitate third-party access to provision and operation of infrastructure facilities, including electricity and telecommunications networks, gas and water pipelines, railroad terminals and networks, airports, and ports. Following these reforms, few countries embarked on a larger scale initiative than Australia to privatize delivery and management of public infrastructure at all levels of government."</ref>

Urban infrastructure ideally serves all residents equally but in practice may prove uneven—with, in some cities, clear first-class and second-class alternatives.<ref name="Lineberry">Robert L. Lineberry, "Mandating Urban Equality: The Distribution of Municipal Public Services"; in Hahn & Levine (1980). See: [[Shaw, Mississippi|Hawkins v. Town of Shaw]] (1971).</ref><ref>{{harvnb| Latham | McCormack | McNamara | McNeill | 2009 | p=75}}: "By the 1960s, however, this 'integrated ideal' was being challenged, public infrastructure entering into crisis. There is now a new orthodoxy in many branches of urban planning: 'The logic is now for planners to fight for the best possible networked infrastructures for their specialized district, in partnership with (often privatised and internationalised network) operators, rather than seeking to orchestrate how networks roll out through the city as a whole" (Graham and Marvin, 2001: 113).<br />In the context of development theory, these 'secessionary' infrastructures physically by-pass sectors of cities unable to afford the necessary cabling, pipe-laying, or streetscaping that underpins service provision. Cities such as Manila, Lagos or Mumbai are thus increasingly characterized by a two-speed mode of urbanization.</ref><ref name=Bakker2003 />

=== Utilities ===
[[File:AcueductoSegovia04.JPG|thumb|[[Aqueduct of Segovia]] in Segovia, Spain]]
[[Public utility|Public utilities]] (literally, useful things with general availability) include basic and essential infrastructure networks, chiefly concerned with the supply of water, electricity, and telecommunications capability to the populace.<ref>"public, adj. and n.", ''Oxford English Dictionary'', September 2007.</ref>

[[Sanitation]], necessary for good health in crowded conditions, requires water supply and [[waste management]] as well as individual [[hygiene]]. Urban [[water]] systems include principally a [[water supply network]] and a network ([[Sewerage|sewerage system]]) for [[sewage]] and [[stormwater]]. [[History of water supply and sanitation|Historically]], either local governments or private companies have administered urban [[water supply]], with a tendency toward government water supply in the 20th century and a tendency toward private operation at the turn of the twenty-first.<ref name=Bakker2003 />{{efn|Water resources in rapidly urbanizing areas are not merely ''privatized'' as they are in western countries; since the systems do not exist to begin with, private contracts also entail water [[Water industry|industrialization]] and [[wikt:enclosure|enclosure]].<ref name=Bakker2003 /> Also, there is a countervailing trend: 100 cities have ''re''-municipalized their water supply since the 1990s.<ref>Emanuele Lobina, David Hall, & Vladimir Popov, "List of water remunicipalisations in Asia and worldwide – As of April 2014"; [[Public Services International Research Unit]], University of Greenwich.</ref>}} The market for private water services is dominated by two French companies, [[Veolia Water]] (formerly [[Vivendi]]) and [[Engie]] (formerly [[Suez (company, 1997–2008)|Suez]]), said to hold 70% of all water contracts worldwide.<ref name=Bakker2003>{{cite journal |author-link=Karen Bakker |first=Karen |last=Bakker |title=Archipelagos and networks: urbanization and water privatization in the South |journal=The Geographical Journal |volume=169 |issue=4 |date=December 2003 |pages=328–341 |doi=10.1111/j.0016-7398.2003.00097.x |bibcode=2003GeogJ.169..328B |quote=The diversity of water supply management systems worldwide—which operate along a continuum between fully public and fully private—bear witness to repeated shifts back and forth between private and public ownership and management of water systems.}}</ref><ref>{{Cite journal |last=Goldman |first=Michael |date=September 2007 |title=How "Water for All!" policy became hegemonic: The power of the World Bank and its transnational policy networks |url=https://www.researchgate.net/publication/222173476 |url-status=live |journal=Geoforum|volume=38 |issue=5 |pages=786–800 |doi=10.1016/j.geoforum.2005.10.008 |archive-url=https://web.archive.org/web/20170918020813/https://www.researchgate.net/profile/Michael_Goldman8/publication/222173476_How_Water_for_All_policy_became_hegemonic_The_power_of_the_World_Bank_and_its_transnational_policy_networks/links/569d1e4408ae03384dd049c5/How-Water-for-All-policy-became-hegemonic-The-power-of-the-World-Bank-and-its-transnational-policy-networks.pdf |archive-date=2017-09-18}}</ref>

Modern urban life relies heavily on the [[energy]] transmitted through [[electricity]] for the operation of [[electric machines]] (from household [[Home appliance|appliances]] to [[outline of industrial machinery|industrial machines]] to now-ubiquitous [[electronics|electronic]] systems used in communications, business, and government) and for [[traffic light]]s, [[street light]]s, and indoor [[lighting]]. Cities rely to a lesser extent on [[hydrocarbon fuel]]s such as [[gasoline]] and [[natural gas]] for transportation, [[heating]], and [[cooking]]. [[Telecommunications]] infrastructure such as [[telephone line]]s and [[coaxial cable]]s also traverse cities, forming dense networks for [[mass communication|mass]] and [[point-to-point (telecommunications)|point-to-point]] communications.{{sfn | Latham | McCormack | McNamara | McNeill | 2009 | pp=169–170}}

=== Transportation ===
{{See also|Public transport}}
[[File:Gautrain..., O R Tambo Intl Airport South Africa.jpg|thumb|[[Gautrain]] at [[O. R. Tambo International Airport]] in Johannesburg]]
[[File:Harmoni Central Busway Transjakarta 4.JPG|thumb|[[TransJakarta]] in Indonesia is the longest [[bus rapid transit]] system in the world.]]
[[File:Kevyen liikenteen väylä Baana - G8541 - hkm.HKMS000005-km0000n5jx.jpg|thumb|[[Baana]], a [[Shared-use path|shared-path]] [[rail trail]] in [[Helsinki]]]]
Because cities rely on specialization and an [[economic system]] based on [[wage labour|wage labor]], their inhabitants must have the ability to regularly travel between home, work, commerce, and entertainment.<ref>Grava (2003), pp. 1–2.</ref> City dwellers travel by foot or by wheel on [[road]]s and [[walkway]]s, or use special [[rapid transit]] systems based on [[tunnel|underground]], [[light rail|overground]], and [[Elevated railway|elevated]] rail. Cities also rely on long-distance transportation (truck, [[rail transport|rail]], and [[airplane]]) for economic connections with other cities and rural areas.<ref name=Hart2001>Tom Hart, "Transport and the City"; in Paddison (2001).</ref>

City streets historically were the domain of [[horse]]s and their riders and [[pedestrian]]s, who only sometimes had [[sidewalk]]s and [[transit mall|special walking areas]] reserved for them.<ref>Grava (2003), pp. 15–18.</ref> In the West, [[bicycle]]s or ([[velocipede]]s), efficient human-powered machines for short- and medium-distance travel,<ref>Grava (2003),</ref> enjoyed a period of popularity at the beginning of the twentieth century before the rise of automobiles.<ref>Smethurst pp. 67–71.</ref> Soon after, they gained a more lasting foothold in Asian and African cities under European influence.<ref>Smethurst pp. 105–171.</ref> In Western cities, industrializing, [[electrification|electrifying]], and expanding [[public transit]] systems, especially [[streetcar]]s, enabled urban expansion as new residential neighborhoods sprang up along transit lines and workers rode to and from work downtown.<ref name=Hart2001 /><ref name="WhittYago1985">{{Cite journal |last1=Whitt |first1=J. Allen |last2=Yago |first2=Glenn |date=September 1985 |title=Corporate Strategies and the Decline of Transit in U.S. Cities |url=http://journals.sagepub.com/doi/10.1177/004208168502100106 |journal=Urban Affairs Quarterly|volume=21 |issue=1 |pages=37–65 |doi=10.1177/004208168502100106 |s2cid=153704300 |issn=0042-0816|url-access=subscription }}</ref>

Since the mid-20th century, cities have relied heavily on [[motor vehicle]] transportation, with major [[effects of the car on societies|implications]] for their layout, environment, and aesthetics.<ref name=Borden>Iain Borden, "Automobile Interstices: Driving and the In-Between Spaces of the City"; in Brighenti (2013).</ref> (This transformation occurred most dramatically in the US—where corporate and governmental policies favored automobile transport systems—and to a lesser extent in Europe.)<ref name=Hart2001 /><ref name=WhittYago1985 /> The rise of personal [[car]]s accompanied the expansion of urban economic areas into much larger [[metropolis]]es, subsequently creating ubiquitous [[traffic]] issues with the accompanying construction of new [[highway]]s, wider streets, and alternative [[walkway]]s for pedestrians.<ref>Moshe Safdie with Wendy Kohn, ''The City After the Automobile''; BasicBooks (HarperCollins), 1997; {{ISBN|0-465-09836-3}}; pp. 3–6.</ref><ref>Grava (2003), pp. 128–132, 152–157.</ref>{{sfn | Latham | McCormack | McNamara | McNeill | 2009 | p=30–32}}<ref name="Wachsmuth2014">{{Cite journal|url=https://www.researchgate.net/publication/275321247|doi=10.1068/d21911|title=City as Ideology: Reconciling the Explosion of the City Form with the Tenacity of the City Concept|journal=Environment and Planning D: Society and Space|volume=32|pages=75–90|year=2014|last1=Wachsmuth|first1=David|issue=1 |bibcode=2014EnPlD..32...75W |s2cid=144077154|access-date=30 June 2017|archive-date=24 October 2018|archive-url=https://web.archive.org/web/20181024192135/https://www.researchgate.net/publication/275321247|url-status=live}}</ref> However, severe traffic jams still occur regularly in cities around the world, as private car ownership and urbanization continue to increase, overwhelming existing urban [[street network]]s.<ref name="Gwilliam2013">{{Cite journal|url=https://www.scribd.com/document/326229357/Cities-on-the-Move-Ten-Years-After|doi=10.1016/j.retrec.2012.06.032|title=Cities on the Move Ten Years After &#124; Biofuel &#124; Economic Growth|journal=Research in Transportation Economics|volume=40|pages=3–18|year=2013|last1=Gwilliam|first1=Kenneth|access-date=30 June 2017|archive-date=28 July 2020|archive-url=https://web.archive.org/web/20200728140827/https://www.scribd.com/document/326229357/Cities-on-the-Move-Ten-Years-After|url-status=live|url-access=subscription}}</ref>

The urban [[Public transport bus service|bus system]], the world's most common form of public transport, uses a network of scheduled [[bus route|routes]] to move people through the city, alongside cars, on the roads.<ref>Grava (2003), 301–305. "There are a great many places where [buses] are the only public service mode offered; to the best of the author's knowledge, no city that has transit operates without a bus component. Leaving aside private cars, all indicators—passengers carried, vehicle kilometers accumulated, size of fleet, accidents recorded, pollution caused, workers employed, or whatever else—show the dominance of buses among all transit modes, in this country as well as anywhere else around the world. [...] At the global scale, there are probably 8000 to 10,000 communities and cities that provide organized bus transit. The larger places have other modes as well, but the bulk of these cities offers buses as their sole public means of mobility."</ref> The economic function itself also became more decentralized as concentration became impractical and employers relocated to more car-friendly locations (including [[edge city|edge cities]]).<ref name=Hart2001 /> Some cities have introduced [[bus rapid transit]] systems which include exclusive [[bus lanes]] and other methods for prioritizing bus traffic over private cars.<ref name="Gwilliam2013" /><ref>{{Cite journal |last1=Levinson |first1=Herbert |last2=Zimmerman |first2=Samuel |last3=Clinger |first3=Jennifer |last4=Rutherford |first4=G. |year=2002 |title=Bus Rapid Transit: An Overview |url=http://scholarcommons.usf.edu/jpt/vol5/iss2/1/ |journal=Journal of Public Transportation |volume=5 |issue=2 |pages=1–30 |doi=10.5038/2375-0901.5.2.1 |s2cid=17621150 |issn=1077-291X|doi-access=free }}</ref> Many big American cities still operate conventional public transit by rail, as exemplified by the ever-popular [[New York City Subway]] system. Rapid transit is widely used in Europe and has increased in Latin America and Asia.<ref name="Gwilliam2013" />

[[Walking]] and [[cycling]] ("non-motorized transport") enjoy increasing favor (more [[pedestrian zone]]s and [[bike lane]]s) in American and Asian urban transportation planning, under the influence of such trends as the [[healthy city|Healthy Cities]] movement, the drive for [[sustainable development]], and the idea of a [[carfree city]].<ref name="Gwilliam2013" /><ref>{{Cite journal |pmc = 3428861|year = 2012|last1 = Rydin|first1 = Y.|title = Shaping cities for health: Complexity and the planning of urban environments in the 21st century|journal = Lancet|volume = 379|issue = 9831|pages = 2079–2108|last2 = Bleahu|first2 = A.|last3 = Davies|first3 = M.|last4 = Dávila|first4 = J.D.|last5 = Friel|first5 = S.|last6 = De Grandis|first6 = G.|last7 = Groce|first7 = N.|last8 = Hallal|first8 = P.C.|last9 = Hamilton|first9 = I.|last10 = Howden-Chapman|first10 = P.|last11 = Lai|first11 = K.M.|last12 = Lim|first12 = C.J.|last13 = Martins|first13 = J.|last14 = Osrin|first14 = D.|last15 = Ridley|first15 = I.|last16 = Scott|first16 = I.|last17 = Taylor|first17 = M.|last18 = Wilkinson|first18 = P.|last19 = Wilson|first19 = J.|pmid = 22651973|doi = 10.1016/S0140-6736(12)60435-8}}</ref><ref>{{Cite journal|url=https://www.academia.edu/17076734|doi=10.1016/j.landurbplan.2004.09.036|title=Greenways: Multiplying and diversifying in the 21st century|journal=Landscape and Urban Planning|volume=76|issue=1–4|pages=252–290|last1=Walmsley|first1=Anthony|year=2006|bibcode=2006LUrbP..76..252W |access-date=20 December 2017|archive-date=10 December 2021|archive-url=https://web.archive.org/web/20211210035741/https://www.academia.edu/17076734|url-status=live}}</ref> Techniques such as [[road space rationing]] and [[road pricing|road use charges]] have been introduced to limit urban car traffic.<ref name="Gwilliam2013" />

== Housing ==
[[File:Winsbury Terrace 75-79 Kent Street Millers Point.jpg|thumb|Horbury Terrace, a [[Terrace house|terrace housing]] in [[Sydney]], {{Circa|1836}}]]
[[Housing|The housing]] of residents presents one of the major challenges every city must face. Adequate housing entails not only physical [[Shelter (building)|shelters]] but also the physical systems necessary to sustain life and economic activity.<ref>McQuillin (1937/1987), §1.74. "It cannot be too strongly emphasized that no city begins to be well-planned until it has solved its housing problem. The problems of living and working are of primary importance. These include sanitation, sufficient sewers, clean, well-lighted streets, rehabilitation of slum areas, and health protection through provision for pure water and wholesome food."</ref>

[[Owner-occupancy|Homeownership]] represents status and a modicum of economic security, compared to [[renting]] which may consume much of the income of low-wage urban workers. [[Homelessness]], or lack of housing, is a challenge currently faced by millions of people in countries rich and poor.<ref>Ray Forrest & Peter Williams, "Housing in the Twentieth Century"; in Paddison (2001).</ref> Because cities generally have higher population densities than rural areas, city dwellers are more likely to reside in [[apartment]]s and less likely to live in a [[Single-family detached home|single-family home]].

==Ecology==
{{Main|Urban ecology}}

[[File:Trash in Paramaribo.JPG|thumb|An urban scene in [[Paramaribo]] featuring a few plants growing amidst [[municipal solid waste|solid waste]] and [[rubble]] behind some houses]]
[[File:Urban heat island (Celsius).png|thumb|An [[urban heat island]]]]
[[File:Dublin Stephen's Green-44 edit.jpg|thumb|[[St Stephen's Green]], an [[urban park]] in [[Dublin]], Ireland]]
Urban [[ecosystem]]s, influenced as they are by the density of human buildings and activities, differ considerably from those of their rural surroundings. Anthropogenic [[building]]s and [[waste]], as well as [[Agriculture|cultivation]] in [[garden]]s, create physical and chemical environments which have no equivalents in the [[wilderness]], in some cases enabling exceptional [[biodiversity]]. They provide homes not only for immigrant humans but also for [[introduced species|immigrant plants]], bringing about interactions between species that never previously encountered each other. They introduce frequent [[disturbance (ecology)|disturbances]] (construction, walking) to plant and animal [[habitat]]s, creating opportunities for [[Secondary succession|recolonization]] and thus favoring [[ecological succession|young ecosystems]] with [[r/K selection theory|r-selected species]] dominant. On the whole, urban ecosystems are less complex and productive than others, due to the diminished absolute amount of biological interactions.<ref>{{Cite journal |last=Rebele |first=Franz |year=1994 |title=Urban Ecology and Special Features of Urban Ecosystems |journal=Global Ecology and Biogeography Letters |volume=4 |issue=6 |pages=173–187 |doi=10.2307/2997649 |jstor=2997649 |issn=0960-7447}}</ref><ref>Herbert Sukopp, "On the Early History of Urban Ecology in Europe"; in Marzluff et al. (2008).</ref><ref name=PickettEtAl2008>S.T.A. Pickett, M.L. Cadenasso, J.M. Grove, C.H. Nilon, R.V. Pouyat, W.C. Zipperer, & R. Costanza, "Urban Ecological Systems: Linking Terrestrial Ecological, Physical, and Socioeconomic Components of Metropolitan Areas"; in Marzluff et al. (2008).</ref><ref>Ingo Kowarik, "On the Role of Alien Species in Urban Flora and Vegetation"; in Marzluff et al. (2008).</ref>

Typical urban [[fauna]] includes [[insect]]s (especially [[ant]]s), [[rodent]]s ([[mouse|mice]], [[rat]]s), and [[bird]]s, as well as [[cat]]s and [[dog]]s ([[domestication|domesticated]] and [[feral]]). Large [[predator]]s are scarce.<ref name=PickettEtAl2008 /> However, in North America, large predators such as coyotes and other large animals like white-tailed deer persist.<ref>{{Cite journal |last1=Gallo |first1=Travis |last2=Fidino |first2=Mason |last3=Lehrer |first3=Elizabeth W. |last4=Magle |first4=Seth B. |year= 2017|title=Mammal diversity and metacommunity dynamics in urban green spaces: implications for urban wildlife conservation |url=https://onlinelibrary.wiley.com/doi/10.1002/eap.1611 |journal=Ecological Applications|volume=27 |issue=8 |pages=2330–2341 |doi=10.1002/eap.1611|pmid=28833978 |bibcode=2017EcoAp..27.2330G |url-access=subscription }}</ref>

Cities generate considerable [[ecological footprint]]s, locally and at longer distances, due to concentrated populations and technological activities. From one perspective, cities are not ecologically [[sustainable]] due to their resource needs. From another, proper management may be able to ameliorate a city's ill effects.<ref>Roberto Camagni, Roberta Capello, & Peter Nijkamp, "Managing Sustainable Urban Environments"; in Paddison (2001).</ref><ref>{{cite web |url=http://www.michellenijhuis.com/ |title=National Geographic Magazine; Special report 2008: Changing Climate: Village Green |publisher=Michelle Nijhuis |date=26 August 2008 |access-date=7 February 2009 |archive-date=15 May 2008 |archive-url=https://web.archive.org/web/20080515234352/http://www.michellenijhuis.com/ |url-status=live }}</ref> [[Air pollution]] arises from various forms of combustion,<ref>{{cite web |url=http://www.aklung.org/air-quality/indoor-air-quality/ |title=Indoor Air Quality&nbsp;– American Lung Association of Alaska |publisher=Aklung.org |access-date=7 February 2009 |archive-url=https://web.archive.org/web/20090211234047/http://www.aklung.org/air-quality/indoor-air-quality/ |archive-date=11 February 2009 }}</ref> including fireplaces, wood or coal-burning stoves, other heating systems,<ref>{{cite web |url=http://newsminer.com/news/2008/aug/20/epa-put-fairbanks-air-pollution-problem-list/ |title=Newsminer.com; EPA to put Fairbanks on air pollution problem list |publisher=Newsminer.com |date=20 August 2008 |access-date=7 February 2009 }}{{dead link|date=December 2017 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> and [[internal combustion engine]]s. Industrialized cities, and today third-world megacities, are notorious for veils of [[smog]] (industrial [[haze]]) that envelop them, posing a chronic threat to the health of their millions of inhabitants.<ref name=Adey2013>Peter Adey, "Coming up for Air: Comfort, Conflict and the Air of the Megacity"; in Brighenti (2013), p. 103.</ref> Urban soil contains higher concentrations of [[heavy metals]] (especially [[lead]], [[copper]], and [[nickel]]) and has lower [[pH]] than soil in the comparable wilderness.<ref name=PickettEtAl2008 />

Modern cities are known for creating their own [[microclimate]]s, due to [[concrete]], [[Asphalt concrete|asphalt]], and other artificial surfaces, which heat up in [[sunlight]] and channel [[rain]]water into [[Storm drain|underground ducts]]. The [[Geography of New York City#Climate|temperature in New York City]] exceeds [[Climate of New York (state)|nearby rural temperatures]] by an average of 2–3&nbsp;°C and at times 5–10&nbsp;°C differences have been recorded. This effect varies nonlinearly with population changes (independently of the city's physical size).<ref name=PickettEtAl2008 /><ref>{{Cite journal |last1=Brazel |first1=Anthony |last2=Selover |first2=Nancy |last3=Vose |first3=Russel |last4=Heisler |first4=Gordon |year=2000 |title=The tale of two climates-Baltimore and Phoenix urban LTER sites |url=https://www.int-res.com/articles/cr/15/c015p123.pdf |url-status=live |journal=Climate Research|volume=15 |pages=123–135 |doi=10.3354/cr015123 |bibcode=2000ClRes..15..123B |issn=0936-577X |archive-url=https://web.archive.org/web/20201022003654/http://www.int-res.com/articles/cr/15/c015p123.pdf |archive-date=2020-10-22}}</ref> Aerial [[particulates]] increase rainfall by 5–10%. Thus, urban areas experience unique climates, with earlier flowering and later leaf dropping than in nearby countries.<ref name=PickettEtAl2008 />

Poor and working-class people face disproportionate exposure to environmental risks (known as [[environmental racism]] when intersecting also with racial segregation). For example, within the urban microclimate, less-vegetated poor neighborhoods bear more of the heat (but have fewer means of coping with it).<ref>Sharon L. Harlan, Anthony J. Brazel, G. Darrel Jenerette, Nancy S. Jones, Larissa Larsen, Lela Prashad, & William L. Stefanov, "In the Shade of Affluence: The Inequitable Distribution of the Urban Heat Island"; in Robert C. Wilkinson & William R. Freudenburg, eds., ''Equity and the Environment'' (Research in Social Problems and Public Policy, Volume 15); Oxford: JAI Press (Elsevier); {{ISBN|978-0-7623-1417-1}}.</ref>

One of the main methods of improving the [[urban ecology]] is including in the cities more [[urban green space]]s: parks, gardens, lawns, and trees. These areas improve the health and well-being of the human, animal, and plant populations of the cities.<ref name="fuller">{{cite journal |last1=Fuller|first1=R.A.|last2=Irvine|first2=K.N.|last3=Devine-Wright|first3=P.|last4=Warren|first4=P.H.|last5=Gaston|first5=K.J. |year=2007 |title=Psychological benefits of green-space increase with biodiversity|journal=Biology Letters|volume=3|issue=4|pages=390–394|doi=10.1098/rsbl.2007.0149 |pmc=2390667|pmid=17504734}}</ref> Well-maintained urban trees can provide many social, ecological, and physical benefits to the residents of the city.<ref>{{Cite journal |last1=Turner-Skoff|first1=J. |last2=Cavender|first2=N. |title=The Benefits of Trees for Livable and Sustainable Communities |journal=Plants, People, Planet |volume=1 |issue=4 |pages=323–335 |year=2019 |doi=10.1002/ppp3.39|doi-access=free |bibcode=2019PlPP....1..323T }}</ref>

A study published in ''[[Scientific Reports]]'' in 2019 found that people who spent at least two hours per week in nature were 23 percent more likely to be satisfied with their life and were 59 percent more likely to be in good health than those who had zero exposure. The study used data from almost 20,000 people in the UK. Benefits increased for up to 300 minutes of exposure. The benefits are applied to men and women of all ages, as well as across different ethnicities, socioeconomic statuses, and even those with long-term illnesses and disabilities. People who did not get at least two hours – even if they surpassed an hour per week – did not get the benefits. The study is the latest addition to a compelling body of evidence for the health benefits of nature. Many doctors already give nature prescriptions to their patients. The study did not count time spent in a person's own yard or garden as time in nature, but the majority of nature visits in the study took place within two miles of home. "Even visiting local urban green spaces seems to be a good thing," Dr. White said in a press release. "Two hours a week is hopefully a realistic target for many people, especially given that it can be spread over an entire week to get the benefit."<ref>{{cite news |last1=Sam Nickerson |first1=Sam |title=Two Hours a Week in Nature Can Boost Your Health and Well-Being, Research Finds |url=https://www.ecowatch.com/nature-time-health-wellness-2638941663.html |access-date=23 June 2019 |agency=Ecowatch |date=21 June 2019 |archive-date=10 December 2021 |archive-url=https://web.archive.org/web/20211210070030/https://www.ecowatch.com/nature-time-health-wellness-2638941663.html |url-status=live }}</ref>

== World city system ==
As the world becomes more closely linked through economics, politics, technology, and culture (a process called [[globalization]]), cities have come to play a leading role in transnational affairs, exceeding the limitations of [[international relations]] conducted by national governments.<ref>Abrahamson (2004), pp. 2–4. "The linkages among cities cutting across nations became a global network. It is important to note here that the key nodes in the international system are (global) cities, not nations. [...] Once the linkages among cities became a global network, nations became dependent upon their major cities for connections to the rest of the world."</ref><ref name=HN2017 /><ref name=Gupta2015globalization>Gupta et al. (2015), 5–11. "Current globalization, characterized by hyper capitalism and technological revolutions, is understood as the growing intensity of economic, demographic, social, political, cultural and environmental interactions worldwide, leading to increasing interdependence and homogenization of ideologies, production and consumption patterns and lifestyles (Pieterse 1994; Sassen 1998). [...] Decentralization processes have increased city-level capacities of city authorities to develop and implement local social and developmental policies. Cities as homes of the rich, and of powerful businesses, banks, stock markets, UN agencies and NGOs, are the location from which global to local decision-making occurs (e.g. New York, London, Paris, Amsterdam, Hong Kong, São Paulo)."</ref> This phenomenon, resurgent today, can be traced back to the [[Silk Road]], [[Phoenicia]], and the Greek city-states, through the [[Hanseatic League]] and other alliances of cities.<ref>Herrschel & Newman (2017), pp. 9–10. "The merchants of the Hanseatic League, for instance, enjoyed substantial trading privileges as a result of inter-city diplomacy and collective agreements within the networks (Lloyd 2002), as well as with larger powers, such as states. That way, the League could negotiate 'extra-territorial' legal spaces with special privileges, such as the 'German Steelyard' in the port of London (Schofield 2012). This special status was granted and guaranteed by the English king as part of an agreement between the state and a foreign city association."</ref><ref name="CalderFreytas2009">{{Cite journal |last1=Calder |first1=Kent E. |last2=de Freytas |first2=Mariko |year=2009 |title=Global Political Cities as Actors in Twenty-First Century International Affairs |url=https://muse.jhu.edu/article/269254 |journal=SAIS Review of International Affairs|volume=29 |issue=1 |pages=79–96 |doi=10.1353/sais.0.0036 |s2cid=154230409 |issn=1945-4724 |quote=Beneath state-to-state dealings, a flurry of activity occurs, with interpersonal networks forming policy communities involving embassies, think tanks, academic institutions, lobbying firms, politicians, congressional staff, research centers, NGOs, and intelligence agencies. This interaction at the level of 'technostructure'—heavily oriented toward information gathering and incremental policy modification—is too complex and voluminous to be monitored by top leadership, yet nevertheless often has important implications for policy.|url-access=subscription }}</ref><ref>Curtis (2016), p. 5.</ref> Today the [[information economy]] based on high-speed [[internet]] infrastructure enables instantaneous [[telecommunication]] around the world, effectively eliminating the distance between cities for the purposes of the international markets and other high-level elements of the world economy, as well as personal communications and [[mass media]].<ref>Kaplan (2004), pp. 115–133.</ref>

=== Global city ===
[[File:London Stock Exchange (13056321704).jpg|thumb|[[Stock exchange]]s, characteristic features of the top global cities, are interconnected hubs for capital. Here, a delegation from Australia visits the [[London Stock Exchange]].]]
A [[global city]], also known as a world city, is a prominent centre of trade, banking, finance, innovation, and markets.<ref>{{cite journal |last1=Engel |first1=Jerome S. |last2=Berbegal-Mirabent |first2=Jasmina |last3=Piqué |first3=Josep M. |title=The renaissance of the city as a cluster of innovation |journal=Cogent Business & Management |year=2018 |volume=5 |issue=1 |article-number=1532777 |doi=10.1080/23311975.2018.1532777 |doi-access=free|hdl=10419/206125 |hdl-access=free }}</ref><ref>{{Cite encyclopedia |title=Global City |url=https://onlinelibrary.wiley.com/doi/10.1002/9781118568446.eurs0514 |encyclopedia=The Wiley Blackwell Encyclopedia of Urban and Regional Studies |last1=Jacobs |first1=Andrew J. |year=2023 |doi=10.1002/9781118568446.eurs0514 |last2=Orum |first2=Anthony M.|pages=1–10 |isbn=978-1-118-56845-3 |s2cid=240985764 |url-access=subscription }}</ref> [[Saskia Sassen]] used the term "global city" in her 1991 work, ''The Global City: New York, London, Tokyo'' to refer to a city's [[Power (social and political)|power]], status, and cosmopolitanism, rather than to its size.<ref>Sassen, Saskia (1991). ''[http://pup.princeton.edu/titles/6943.html The Global City: New York, London, Tokyo.]'' {{webarchive|url=https://web.archive.org/web/20150316103717/http://pup.princeton.edu/titles/6943.html |date=16 March 2015 }} [[Princeton University Press]]. {{ISBN|0-691-07063-6}}</ref> Following this view of cities, it is possible to [[Global city#GaWC study|rank the world's cities hierarchically]].<ref name=ranking>John Friedmann and Goetz Wolff, "World City Formation: An Agenda for Research and Action", ''International Journal of Urban and Regional Research'', 6, no. 3 (1982): 319</ref> Global cities form the capstone of the global hierarchy, exerting [[command and control]] through their economic and political influence. Global cities may have reached their status due to early transition to [[post-industrial society|post-industrialism]]<ref>Abrahamson (2004), p. 4. "The formerly major industrial cities that were most able quickly and thoroughly to transform themselves into the new postindustrial mode became the leading global cities—the centers of the new global system."</ref> or through inertia which has enabled them to maintain their dominance from the industrial era.<ref>Kaplan et al. (2004), p. 88.</ref> This type of ranking exemplifies an emerging [[discourse]] in which cities, considered variations on the same ideal type, ''must'' compete with each other globally to achieve prosperity.<ref name=Ward2008 /><ref name=Wachsmuth2014 />

Critics of the notion point to the different realms of power and interchange. The term "global city" is heavily influenced by economic factors and, thus, may not account for places that are otherwise significant. [[Paul James (academic)|Paul James]], for example argues that the term is "reductive and skewed" in its focus on financial systems.<ref>{{Cite book | last1= James | first1= Paul | author-link= Paul James (academic) | last2= with Magee | first2= Liam | last3= Scerri | first3= Andy | last4= Steger | first4= Manfred B. | title= Urban Sustainability in Theory and Practice: Circles of Sustainability | url= https://www.academia.edu/9294719 | year= 2015 | publisher= Routledge | location= London | pages= 28, 30 | isbn= 978-1-315-76574-7 | access-date= 20 December 2017 | archive-date= 1 March 2020 | archive-url= https://web.archive.org/web/20200301210732/https://www.academia.edu/9294719 | url-status= live|quote=Against those writers who, by emphasizing the importance of financial exchange systems, distinguish a few special cities as 'global cities'—commonly London, Paris, New York and Tokyo—we recognize the uneven global dimensions of all the cities that we study. Los Angeles, the home of Hollywood, is a globalizing city, though perhaps more significantly in cultural than economic terms. And so is Dili globalizing, the small and 'insignificant' capital of Timor Leste—except this time it is predominantly in political terms...}}</ref>

[[Multinational corporation]]s and [[bank]]s make their headquarters in global cities and conduct much of their business within this context.<ref>Kaplan (2004), 99–106.</ref> American firms dominate the international markets for [[law firm|law]] and [[engineering]] and maintain branches in the biggest foreign global cities.<ref>Kaplan (2004), pp. 91–95. "The United States is also dominant in providing high-quality, global engineering-design services, accounting for approximately 50 percent of the world's total exports. The disproportionate presence of these U.S.-headquartered firms is attributable to the U.S. role in overseas automobile production, the electronics and petroleum industries, and various kinds of construction, including work on the country's numerous overseas air and navy military bases."</ref>

Large cities have a great divide between populations of both ends of the financial spectrum.<ref>Kaplan (2004), pp. 90–92.</ref> Regulations on immigration promote the exploitation of low- and high-skilled immigrant workers from poor areas.<ref>{{Cite journal |last=Samers |first=Michael |date=2002-06-28 |title=Immigration and the Global City Hypothesis: Towards an Alternative Research Agenda |url=https://www.academia.edu/9294719 |url-status=live |journal=International Journal of Urban and Regional Research|volume=26 |issue=2 |pages=389–3402 |doi=10.1111/1468-2427.00386 |issn=0309-1317 |archive-url=https://web.archive.org/web/20200301210732/https://www.academia.edu/9294719 |archive-date=2020-03-01 |quote=And not withstanding some major world cities that do not have comparatively high levels of immigration, like Tokyo, it may in fact be the presence of such large-scale immigrant economic 'communities' (with their attendant global financial remittances and their ability to incubate small business growth, rather than their complementarity to producer services employment) which partially distinguishes mega-cities from other more nationally oriented urban centres.|doi-access=free }}</ref><ref>{{Cite book |last1=Willis |first1=Jane |title=Global cities at work: new migrant divisions of labour |last2=Datta |first2=Kavita |last3=Evans |first3=Yara |last4=Herbert |first4=Joanna |last5=May |first5=John |last6=McIlwane |first6=Cathy |publisher=Pluto Press |year=2010 |isbn=978-0-7453-2799-0 |editor-last=Wills |editor-first=Jane |location=London |page=29 |quote=These apparently rather different takes on London's 'global city' status are of course not so far removed from one another as they may first appear. Holding them together is the figure of the migrant worker. The reliance of London's financial institutions and business services industries on the continuing flow of highly skilled labour from overseas is now well known (Beaverstock and Smith 1996). Less well known is the extent to which London's economy as a whole is now dependent upon the labour power of low-paid workers from across the world.}}</ref><ref>{{Cite journal |last1=Sanderson |first1=Matthew R |last2=Derudder |first2=Ben |last3=Timberlake |first3=Michael |last4=Witlox |first4=Frank |date=June 2015 |title=Are world cities also world immigrant cities? An international, cross-city analysis of global centrality and immigration |url=http://journals.sagepub.com/doi/10.1177/0020715215604350 |journal=International Journal of Comparative Sociology|volume=56 |issue=3–4 |pages=173–197 |doi=10.1177/0020715215604350 |s2cid=153828266 |issn=0020-7152|url-access=subscription }}</ref> During employment, migrant workers may be subject to unfair working conditions, including working overtime, low wages, and lack of safety in workplaces.{{sfn| Latham | McCormack | McNamara | McNeill | 2009 | pp=49–50}}

{{Wide image|10 mile panorama of NYC, Feb., 2018.jpg|1800px|3=Modern global cities, like [[New York City]], often include large [[central business district]]s (CBDs) that serve as hubs for economic activity. A panorama of [[Manhattan]], the world's largest central business district, is shown with prominent buildings highlighted by number, February 2018.{{flatlist|
# [[Riverside Church]]
# [[Deutsche Bank Center]]
# [[220 Central Park South]]
# [[Central Park Tower]]
# [[One57]]
# [[432 Park Avenue]]
# [[53W53]]
# [[Chrysler Building]]
# [[Bank of America Tower (Manhattan)|Bank of America Tower]]
# [[4 Times Square]]
# [[The New York Times Building]]
# [[Empire State Building]]
# [[Manhattan West]]
# a: [[55 Hudson Yards]], b: [[35 Hudson Yards]], c: [[10 Hudson Yards]], d: [[15 Hudson Yards]]
# [[56 Leonard Street]]
# [[8 Spruce Street]]
# [[Woolworth Building]]
# [[70 Pine Street]]
# [[Four Seasons Hotel New York Downtown]]
# [[40 Wall Street]]
# [[3 World Trade Center]]
# [[4 World Trade Center]]
# [[One World Trade Center]]}}
|align-cap=center}}

=== Transnational activity ===
Cities increasingly participate in world political activities independently of their enclosing nation-states. Early examples of this phenomenon are the [[sister city]] relationship and the promotion of [[multi-level governance]] within the European Union as a technique for [[European integration]].<ref name=HN2017>Herrschel & Newman (2017), pp. 3–4. "Instead, the picture is becoming more detailed and differentiated, with a growing number of sub-national entities, cities, city-regions and regions, becoming more visible in their own right, either individually, or collectively as networks, by, more or less tentatively, stepping out of the territorial canvas and hierarchical institutional hegemony of the state. Prominent and well-known cities, and those regions with a strong sense of identity and often a quest for more autonomy, have been the most enthusiastic, as they began to be represented beyond state borders by high-profile city mayors and some regional leaders with political courage and agency. [...] This, then, became part of the much bigger political project of the European Union (EU), which has offered a particularly supportive environment for international engagement by—and among—subnational governments as part of its inherent integrationist agenda."</ref><ref>Charlie Jeffery, "[http://aei.pitt.edu/2635/1/002803_1.PDF Sub-National Authorities and European Integration: Moving Beyond the Nation-State?] {{Webarchive|url=https://web.archive.org/web/20181103170402/http://aei.pitt.edu/2635/1/002803_1.PDF |date=3 November 2018 }}", presented at the Fifth Biennial International Conference of the European Community Studies Association, 29 May–1 June 1997, Seattle, US.</ref><ref>Jing Pan, "[https://www.dora.dmu.ac.uk/xmlui/bitstream/handle/2086/11117/JING%20PAN%20PhD%20Thesis-Final-confirmed.pdf?sequence=1&isAllowed=y The Role of Local Government in Shaping and Influencing International Policy Frameworks] {{Webarchive|url=https://web.archive.org/web/20171010004951/https://www.dora.dmu.ac.uk/xmlui/bitstream/handle/2086/11117/JING%20PAN%20PhD%20Thesis-Final-confirmed.pdf?sequence=1&isAllowed=y |date=2017-10-10 }}", PhD thesis accepted at De Montfort University, April 2014.</ref> Cities including [[Hamburg]], [[Prague]], [[Amsterdam]], [[The Hague]], and [[City of London]] maintain their own embassies to [[Brussels and the European Union|the European Union at Brussels]].<ref>Herrschel & Newman (2017), p. "In Europe, the EU provides incentives and institutional frameworks for multiple new forms of city and regional networking and lobbying, including at the international EU level. But a growing number of cities and regions also seek to 'go it alone' by establishing their own representations in Brussels, either individually or in shared accommodation, as the base for European lobbying."</ref><ref>{{Cite journal |last1=Marks |first1=Gary |last2=Haesly |first2=Richard |last3=Mbaye |first3=Heather A.D. |date=Autumn 2002 |title=What Do Subnational Offices Think They Are Doing in Brussels? |url=https://garymarks.web.unc.edu/wp-content/uploads/sites/13018/2016/09/marks.haesly.mbaye_.subnational_offices_2002.pdf |url-status=live |journal=Regional & Federal Studies|volume=12 |issue=3 |pages=1–23 |doi=10.1080/714004755 |s2cid=154556467 |issn=1359-7566 |archive-url=https://web.archive.org/web/20180128112850/http://garymarks.web.unc.edu/files/2016/09/marks.haesly.mbaye_.subnational_offices_2002.pdf |archive-date=2018-01-28}}</ref><ref>Carola Hein, "[http://www.tandfonline.com/doi/full/10.1080/12265934.2014.980304 Cities (and regions) within a city: subnational representations and the creation of European imaginaries in Brussels] {{Webarchive|url=https://web.archive.org/web/20181116125130/https://www.tandfonline.com/doi/full/10.1080/12265934.2014.980304 |date=16 November 2018 }}"; ''International Journal of the Urban Sciences'' 19(1), 2015. See also websites of individual city embassies cited therein, including [http://hanse-office.de/index.php?article_id=5&clang=1 Hanse Office] {{Webarchive|url=https://web.archive.org/web/20170101104104/http://hanse-office.de/index.php?article_id=5&clang=1 |date=1 January 2017 }} (Hamburg and Schleswig-Holstein) and City of London "[https://www.cityoflondon.gov.uk/business/eu-and-regulation/city-office-brussels/Pages/default.aspx City Office in Brussels] {{Webarchive|url=https://web.archive.org/web/20170816125811/https://www.cityoflondon.gov.uk/business/eu-and-regulation/city-office-brussels/Pages/default.aspx |date=2017-08-16 }}"; and CoR's [cor.europa.eu/en/regions/Documents/regional-offices.xls spreadsheet of regional offices] in Brussels.</ref>

New urban dwellers are increasingly [[transmigrants]], keeping one foot each (through telecommunications if not travel) in their old and their new homes.{{sfn| Latham | McCormack | McNamara | McNeill | 2009 | pp=45–47}}

=== Global governance ===
Cities participate in [[global governance]] by various means including membership in global networks which transmit norms and regulations. At the general, global level, [[United Cities and Local Governments]] (UCLG) is a significant [[umbrella organization]] for cities; regionally and nationally, [[Eurocities]], [[Asian Network of Major Cities 21]], the [[Federation of Canadian Municipalities]] the [[National League of Cities]], and the [[United States Conference of Mayors]] play similar roles.<ref name="Bouteligier2013">{{Cite journal |last=Bouteligier |first=Sofie |year=2013 |title=Inequality in new global governance arrangements: the North–South divide in transnational municipal networks |url=https://edepot.wur.nl/238650 |url-status=live |journal=Innovation: The European Journal of Social Science Research|volume=26 |issue=3 |pages=251–267 |doi=10.1080/13511610.2013.771890 |s2cid=143765511 |issn=1351-1610 |archive-url=https://web.archive.org/web/20171010005116/http://edepot.wur.nl/238650 |archive-date=2017-10-10|url-access=subscription }}</ref><ref name=HN2017p82>Herrschel & Newman (2017), p. 82.</ref> UCLG took responsibility for creating [[Agenda 21 for culture]], a program for [[cultural policy|cultural policies]] promoting sustainable development, and has organized various conferences and reports for its furtherance.<ref name=DuxburyJeannotte2013>Nancy Duxbury & Sharon Jeannotte, "[http://www.ces.uc.pt/myces/UserFiles/livros/1097_Global_Cultural_Governance_Policy_Duxbury-Jeannotte_2013.pdf Global Cultural Governance Policy] {{Webarchive|url=https://web.archive.org/web/20210429163239/http://www.ces.uc.pt/myces/UserFiles/livros/1097_Global_Cultural_Governance_Policy_Duxbury-Jeannotte_2013.pdf |date=29 April 2021 }}"; Chapter 21 in ''The Ashgate Research Companion to Planning and Culture''; London: Ashgate, 2013.</ref>

Networks have become especially prevalent in the arena of [[environmentalism]] and specifically [[climate change]] following the adoption of [[Agenda 21]]. Environmental city networks include the [[C40 Cities Climate Leadership Group]], the [[United Nations Global Compact#UN Global Compact – Cities Programme|United Nations Global Compact Cities Programme]], the [[Carbon Neutral Cities Alliance]] (CNCA), the [[Covenant of Mayors]] and the [[Compact of Mayors]],<ref>Now the [[Global Covenant of Mayors]]; see: {{cite web|url=https://www.compactofmayors.org/globalcovenantofmayors/|title=Global Covenant of Mayors – Compact of Mayors|access-date=13 October 2016|archive-url=https://web.archive.org/web/20161014062217/https://www.compactofmayors.org/globalcovenantofmayors/|archive-date=14 October 2016}}</ref> [[ICLEI|ICLEI – Local Governments for Sustainability]], and the [[Transition town|Transition Towns network]].<ref name=Bouteligier2013 /><ref name=HN2017p82 />

Cities hold world political status as meeting places for advocacy groups, non-governmental organizations, lobbyists, educational institutions, intelligence agencies, military contractors, information technology firms, and other groups with a stake in world policymaking. They are consequently also sites for symbolic protest.<ref name=CalderFreytas2009 />{{efn|One important global political city, described at one time as a [[Caput Mundi|world capital]], is [[Washington, D.C.]] and [[Washington metropolitan area|its metropolitan area]], including [[Tysons, Virginia|Tysons]] and [[Reston, Virginia|Reston]] in the [[Dulles Technology Corridor]] and the various federal agencies found along the [[Baltimore–Washington Parkway]]). Beyond the prominent institutions of U.S. government on the national mall, this area contains [[List of diplomatic missions in Washington, DC|177 embassies]], [[The Pentagon]], the [[George Bush Center for Intelligence|Central Intelligence Agency headquarters]], the World Bank headquarters, myriad [[think tank]]s and [[lobbyist|lobbying groups]], and corporate headquarters for [[Booz Allen Hamilton]], [[General Dynamics]], [[Capital One]], [[Verisign]], [[Mortgage Electronic Registration Systems]], and [[Gannett Company]].<ref name=CalderFreytas2009 />}}

[[South Africa]] has one of the highest rates of protests in the world.<ref>{{Cite news |date=2022-08-24 |title=South Africans in nationwide strike in protest against cost of living|publisher=BBC News |url=https://www.bbc.com/news/world-africa-62659893 |access-date=2023-08-16}}</ref>

=== United Nations System ===
[[File:World Bank building at Washington.jpg|thumb|The [[World Bank]] headquarters in [[Washington, D.C.]]]]
[[File:X World Assembly of Mayors - Quito (01).jpg|thumb|The World Assembly of Mayors at the [[Habitat III]] conference in [[Quito]]]]
The [[United Nations System]] has been involved in a series of events and declarations dealing with the development of cities during this period of rapid urbanization.
* The [[Habitat I]] conference in 1976 adopted the "Vancouver Declaration on Human Settlements" which identifies urban management as a fundamental aspect of [[economic development|development]] and establishes various principles for maintaining urban [[habitat]]s.<ref>"[https://web.archive.org/web/20040915005846/http://habitat.igc.org/vancouver/vp-intr.htm The Vancouver Action Plan]"; Approved at Habitat: United Nations Conference on Human Settlements, Vancouver, Canada; 31 May to 11 June 1976.</ref>
* Citing the Vancouver Declaration, the UN General Assembly in December 1977 authorized the United Nations Commission Human Settlements and the HABITAT Centre for Human Settlements, intended to coordinate UN activities related to housing and settlements.<ref name="Walker2005">{{Cite journal |last=Walker |first=Peter R. |year=2005 |title=Human Settlements and Urban Life: A United Nations Perspective |url=https://www.tandfonline.com/doi/full/10.1179/105307805807066329 |journal=Journal of Social Distress and the Homeless|volume=14 |issue=1–2 |pages=65–71 |doi=10.1179/105307805807066329 |s2cid=145470124 |issn=1053-0789|url-access=subscription }}</ref>
* The 1992 [[Earth Summit]] in [[Rio de Janeiro]] resulted in a set of international agreements including [[Agenda 21]] which establishes principles and plans for [[sustainable development]].<ref>{{cite journal | last=Satterthwaite | first=David | title=A new urban agenda? | journal=Environment and Urbanization | volume=28 | issue=1 | date=2016 | issn=0956-2478 | doi=10.1177/0956247816637501 | pages=3–12| bibcode=2016EnUrb..28....3S }}</ref>
* The [[Habitat II]] conference in 1996 called for cities to play a leading role in this program, which subsequently advanced the [[Millennium Development Goals]] and [[Sustainable Development Goals]].<ref name= Parnell>{{Cite journal |last=Parnell |first=Susan |year=2015 |title=Defining a Global Urban Development Agenda |url=https://linkinghub.elsevier.com/retrieve/pii/S0305750X15002508 |journal=World Development|volume=78 |pages=531–532 |doi=10.1016/j.worlddev.2015.10.028 |quote=Garnered by its interest in the urban poor the Bank, along with other international donors, became an active and influential participant in the Habitat deliberations, confirming both Habitat I and Habitat II's focus on 'development in cities' instead of the role of 'cities in development'.|url-access=subscription }}</ref>
* In January 2002 the UN Commission on Human Settlements became an umbrella agency called the [[United Nations Human Settlements Programme]] or UN-Habitat, a member of the [[United Nations Development Group]].<ref name=Walker2005 />
* The [[Habitat III]] conference of 2016 focused on implementing these goals under the banner of a "New Urban Agenda". The four mechanisms envisioned for effecting the New Urban Agenda are (1) national policies promoting integrated sustainable development, (2) stronger urban governance, (3) long-term integrated urban and territorial planning, and (4) effective financing frameworks.<ref name= Watson2016>{{Cite journal |last=Watson |first=Vanessa |date=November 2016 |title=Locating planning in the New Urban Agenda of the urban sustainable development goal |url=http://journals.sagepub.com/doi/10.1177/1473095216660786 |journal=Planning Theory|volume=15 |issue=4 |pages=435–448 |doi=10.1177/1473095216660786 |s2cid=151556078 |issn=1473-0952|url-access=subscription }}</ref><ref>''[http://habitat3.org/the-new-urban-agenda/ New Urban Agenda] {{Webarchive|url=https://web.archive.org/web/20210428073612/http://habitat3.org/the-new-urban-agenda/ |date=28 April 2021 }}'', Habitat III Secretariat, 2017; A/RES/71/256*; {{ISBN|978-92-1-132731-1}}; p. 15.</ref> Just before this conference, the [[European Union]] concurrently approved an "Urban Agenda for the European Union" known as the [[Pact of Amsterdam]].<ref name= Watson2016/>

UN-Habitat coordinates the U.N. urban agenda, working with the [[UN Environmental Programme]], the [[UN Development Programme]], the [[Office of the High Commissioner for Human Rights]], the [[World Health Organization]], and the [[World Bank]].<ref name=Walker2005 />

The [[World Bank]], a U.N. [[List of specialized agencies of the United Nations|specialized agency]], has been a primary force in promoting the Habitat conferences, and since the first Habitat conference has used their declarations as a framework for issuing loans for urban infrastructure.<ref name= Parnell/> The bank's [[structural adjustment]] programs contributed to urbanization in the [[Third World]] by creating incentives to move to cities.<ref>[[Akin Mabogunje|Akin L. Mabogunje]], "A New Paradigm for Urban Development"; ''Proceedings of the World Bank Annual Conference on Development Economics 1991''. "Irrespective of the economic outcome, the regime of structural adjustment being adopted in most developing countries today is likely to spur urbanization. If structural adjustment actually succeeds in turning around economic performance, the enhanced gross domestic product is bound to attract more migrants to the cities; if it fails, the deepening misery—especially in the rural areas—is certain to push more migrants to the city."</ref><ref>John Briggs and Ian E.A. Yeboah, "[http://eprints.gla.ac.uk/169/1/Briggs,J_33.pdf Structural adjustment and the contemporary sub-Saharan African city] {{Webarchive|url=https://web.archive.org/web/20181113035712/http://eprints.gla.ac.uk/169/1/Briggs,J_33.pdf |date=13 November 2018 }}"; ''Area'' 33(1), 2001.</ref> The World Bank and UN-Habitat in 1999 jointly established the [[Cities Alliance]] (based at the World Bank headquarters in Washington, D.C.) to guide policymaking, knowledge sharing, and [[Grant (money)|grant]] distribution around the issue of urban poverty.<ref>Claire Wanjiru Ngare, "[https://ruor.uottawa.ca/bitstream/10393/22844/3/Wanjiru_Claire_2012_researchpaper.pdf Supporting Learning Cities: A Case Study of the Cities Alliance] {{Webarchive|url=https://web.archive.org/web/20160304191410/http://www.ruor.uottawa.ca/bitstream/10393/22844/3/Wanjiru_Claire_2012_researchpaper.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.ruor.uottawa.ca/bitstream/10393/22844/3/Wanjiru_Claire_2012_researchpaper.pdf |archive-date=2022-10-09 |url-status=live |date=4 March 2016 }}"; master's thesis accepted at the University of Ottawa, April 2012.</ref> (UN-Habitat plays an advisory role in evaluating the quality of a locality's governance.)<ref name=Gupta2015p33 /> The Bank's policies have tended to focus on bolstering [[real estate]] markets through credit and technical assistance.<ref>{{Cite journal |last=Frediani |first=Alexandre Apsan |year=2007 |title=Amartya Sen, the World Bank, and the Redress of Urban Poverty: A Brazilian Case Study |url=https://www.rrojasdatabank.info/urban/alexurbpov.pdf |url-status=live |journal=Journal of Human Development|volume=8 |issue=1 |pages=133–152 |doi=10.1080/14649880601101473 |s2cid=14934410 |issn=1464-9888 |archive-url=https://web.archive.org/web/20180721104755/http://www.rrojasdatabank.info/urban/alexurbpov.pdf |archive-date=2018-07-21}}</ref>

The United Nations Educational, Scientific and Cultural Organization ([[UNESCO]]) has increasingly focused on cities as key sites for influencing [[cultural governance]]. It has developed various city networks including the International Coalition of Cities against Racism and the Creative Cities Network. UNESCO's capacity to select [[World Heritage Site]]s gives the organization significant influence over [[cultural capital]], [[tourism]], and [[historic preservation]] funding.<ref name=DuxburyJeannotte2013 />

== Representation in culture ==
{{Further|Urban fiction}}
[[File:The fall of Babylon; Cyrus the Great defeating the Chaldean Wellcome V0034440.jpg|thumb|''The Fall of Babylon'', an 1831 portrait by [[John Martin (painter)|John Martin]], depicts chaos with the Persian army occupying [[Babylon]], symbolizing the ruin of a decadent civilization. The lightning striking the [[Etemenanki|Babylonian ziggurat]] represents the [[Tower of Babel]] and God's judgment against Babylon.]]
Cities figure prominently in traditional Western culture, appearing in the [[Bible]] in both evil and holy forms, symbolized by [[Babylon]] and [[Jerusalem]].<ref>Ellul (1970).</ref> [[Cain]] and [[Nimrod]] are the first city builders in the [[Book of Genesis]]. In Sumerian mythology [[Gilgamesh]] built the walls of [[Uruk]].

Cities can be perceived in terms of extremes or opposites: at once liberating and oppressive, wealthy and poor, organized and chaotic.<ref>Bridge, Gary; Watson, Sophie. "City Imaginaries", in Bridge & Watson, eds. (2000).</ref> The name [[anti-urbanism]] refers to various types of ideological opposition to cities, whether because of their culture or their political relationship with [[Rural area|the country]]. Such opposition may result from identification of cities with oppression and the ruling [[elite]].<ref>Herrschel & Newman (2017), pp. 7–8. "Growing inequalities as a result of neo-liberal globalism, such as between the successful cities and the less successful, struggling, often peripheral, cities and regions, produce rising political discontent, such as we are now facing across Europe and in the United States as populist accusations of self-serving metropolitan elitism."</ref> This and other political ideologies strongly influence narratives and themes in [[discourse]] about cities.<ref name= KAL/> In turn, cities symbolize their home societies.<ref>[[J.E. Cirlot]], "City"; ''A Dictionary of Symbols'', 2nd ed., translated from Spanish to English by Jack Read; New York: Philosophical Library, 1971; pp. 48–49 ([https://archive.org/stream/DictionaryOfSymbols/Dictionary%20of%20Symbols#page/n103/mode/2up online]).</ref>

Writers, painters, and filmmakers have produced innumerable works of art concerning the urban experience. Classical and medieval literature includes a genre of ''[[List of literary descriptions of cities (before 1550)|descriptiones]]'' which treat of city features and history. Modern authors such as [[Charles Dickens]] and [[James Joyce]] are famous for evocative descriptions of their home cities.{{sfn| Latham | McCormack | McNamara | McNeill | 2009 | p=115}} [[Fritz Lang]] conceived the idea for his influential 1927 film ''[[Metropolis (1927 film)|Metropolis]]'' while visiting [[Times Square]] and marveling at the nighttime [[neon lighting]].<ref>Leach (1993), p. 345. "The German film director Fritz Lang was inspired to 'make a film' about 'the sensations' he felt when he first saw Times Square in 1923; a place 'lit as if in full daylight by neon lights and topping them oversized luminous advertisements moving, turning, flashing on and off ... something completely new and nearly fairly-tale-like for a European ... a luxurious cloth hung from a dark sky to dazzle, distract, and hypnotize.' The film Lang made turned out to be ''The Metropolis'', an unremittingly dark vision of a modern industrial city."</ref> Other early cinematic representations of cities in the twentieth century generally depicted them as technologically efficient spaces with smoothly functioning systems of automobile transport. By the 1960s, however, [[traffic congestion]] began to appear in such films as ''[[The Fast Lady]]'' (1962) and ''[[Playtime]]'' (1967).<ref name= Borden/>

Literature, film, and other forms of popular culture have supplied visions of future cities both [[utopia]]n and [[dystopia]]n. The prospect of expanding, communicating, and increasingly interdependent world cities has given rise to images such as [[Nylonkong]] (New York, London, Hong Kong)<ref>Curtis (2016), pp. vii–x, 1.</ref> and visions of a single world-encompassing [[ecumenopolis]].<ref>[[Constantinos Apostolou Doxiadis]], ''[http://www.doxiadis.org/ViewArticle.aspx?ArticleId=14929 Ecumenopolis: Tomorrow's City] {{Webarchive|url=https://web.archive.org/web/20171010005729/http://www.doxiadis.org/ViewArticle.aspx?ArticleId=14929 |date=10 October 2017 }}''; Britannica Book of the Year, 1968. Chapter V: Ecumenopolis, the Real City of Man. "Ecumenopolis, which mankind will have built 150 years from now, can be the real city of man because, for the first time in history, man will have one city rather than many cities belonging to different national, racial, religious, or local groups, each ready to protect its own members but also ready to fight those from other cities, large and small, interconnected into a system of cities. Ecumenopolis, the unique city of man, will form a continuous, differentiated, but also unified texture consisting of many cells, the human communities."</ref>

==Gallery==
{{gallery
|height=150
|width=200
|File:Kartie Sakhali old grave yard - panoramio - Masoud Akbari.jpg|Hillside housing and a [[cemetery]] in [[Kabul]], Afghanistan
|File:Piraeus map 1908.jpg|Map of [[Piraeus]], designed according to the [[Hippodamus of Miletus|Hippodameian]] grid plan
|File:Penang City Hall.jpg|The [[City Hall, George Town|city hall in George Town]], Malaysia, serves as the [[seat of local government|seat]] of [[Penang Island City Council]].<ref>[[Penang Island]] was incorporated as a single municipality in 1976 and gained [[city status]] in 2015. See: Royce Tan, "[http://www.thestar.com.my/news/nation/2014/12/18/penang-island-gets-city-status-mbpp-set-to-take-over-as-new-city-council/ Penang island gets city status] {{Webarchive|url=https://web.archive.org/web/20170629204236/http://www.thestar.com.my/news/nation/2014/12/18/penang-island-gets-city-status-mbpp-set-to-take-over-as-new-city-council/ |date=29 June 2017 }}", ''The Star'', 18 December 2014.</ref>
|File:Warsaw Old Town 1945.jpg| Warsaw Old Town after the [[Warsaw uprising]] with 85% of the city [[Aftermath of the Warsaw Uprising|destroyed]]
|File:Central Park - The Pond (48377220157).jpg| [[Central Park]] in New York City
}}

==See also==
{{Portal|Cities}}
* [[Lists of cities]]
* [[List of adjectivals and demonyms for cities]]
* [[Compact city]]
* [[Eco-cities]]
* [[Lost city]]
* [[Megacity]]
* [[Metropolis]]
* [[Settlement hierarchy]]
* [[Urbanization]]
* [[Walking city]]

== Notes ==
{{notelist}}
{{clear}}

==References==
{{Reflist}}

===Bibliography===
{{refbegin}}
* Abrahamson, Mark (2004). ''Global Cities''. Oxford University Press. {{ISBN|0-19-514204-7}}
* Ashworth, G.J. ''War and the City''. London & New York: Routledge, 1991. {{ISBN|0-203-40963-9}}.
* {{Cite book|last=Bairoch|first=Paul|year=1988|title=Cities and Economic Development: From the Dawn of History to the Present|isbn=978-0-226-03465-2|publisher=[[University of Chicago Press]]|location=Chicago|url=https://archive.org/details/citieseconomicde0000bair}}
* Bridge, Gary, and Sophie Watson, eds. (2000). ''A Companion to the City''. Malden, MA: Blackwell, 2000/2003. {{ISBN|0-631-21052-0}}
* Brighenti, Andrea Mubi, ed. (2013). ''Urban Interstices: The Aesthetics and the Politics of the In-between.'' Farnham: [[Ashgate Publishing]]. {{ISBN|978-1-4724-1002-3}}.
* Carter, Harold (1995). ''The Study of Urban Geography''. 4th ed. London: Arnold. {{ISBN|0-7131-6589-8}}
* Clark, Peter (ed.) (2013). ''The Oxford Handbook of Cities in World History''. Oxford University Press. {{ISBN|978-0-19-175036-6}}
* Curtis, Simon (2016). ''Global Cities and Global Order''. Oxford University Press. {{ISBN|978-0-19-874401-6}}
* [[Jacques Ellul|Ellul, Jacques]] (1970). ''[[The Meaning of the City]]''. Translated by Dennis Pardee. Grand Rapids, Michigan: Eerdmans, 1970. {{ISBN|978-0-8028-1555-2}}; French original (written earlier, published later as): [[:fr:Sans feu ni lieu : Signification biblique de la Grande Ville|Sans feu ni lieu : Signification biblique de la Grande Ville]]; Paris: Gallimard, 1975. Republished 2003 with {{ISBN|978-2-7103-2582-6}}
* Gupta, Joyetta, Karin Pfeffer, Hebe Verrest, & Mirjam Ros-Tonen, eds. (2015). ''Geographies of Urban Governance: Advanced Theories, Methods and Practices''. Springer, 2015. {{ISBN|978-3-319-21272-2}}.
* Hahn, Harlan, & Charles Levine (1980). ''Urban Politics: Past, Present, & Future''. New York & London: Longman.
* Hanson, Royce (ed.). ''[https://www.nap.edu/read/561/chapter/1 Perspectives on Urban Infrastructure]''. Committee on National Urban Policy, Commission on Behavioral and Social Sciences and Education, National Research Council. Washington: National Academy Press, 1984.
* Herrschel, Tassilo & Peter Newman (2017). ''Cities as International Actors: Urban and Regional Governance Beyond the Nation State''. Palgrave Macmillan ([[Springer Nature]]). {{ISBN|978-1-137-39617-4}}
* {{Cite book|last=Jacobs|first=Jane|year=1969|title=The Economy of Cities|place=New York|publisher=Random House Inc}}
* Grava, Sigurd (2003). ''Urban Transportation Systems: Choices for Communities''. McGraw Hill, e-book. {{ISBN|978-0-07-147679-9}}
* {{Cite book | last1= James | first1= Paul | author-link= Paul James (academic) | last2= with Magee | first2= Liam | last3= Scerri | first3= Andy | last4= Steger | first4= Manfred B. | title= Urban Sustainability in Theory and Practice: Circles of Sustainability | url= https://www.academia.edu/9294719 | year= 2015 | publisher= Routledge | location= London| isbn= 978-1-315-76574-7 }}
* Kaplan, David H.; James O. Wheeler; Steven R. Holloway; & Thomas W. Hodler, cartographer (2004). ''Urban Geography''. John Wiley & Sons, Inc. {{ISBN|0-471-35998-X}}
* Kavaratzis, Mihalis, Gary Warnaby, & Gregory J. Ashworth, eds. (2015). ''Rethinking Place Branding: Comprehensive Brand Development for Cities and Regions''. Springer. {{ISBN|978-3-319-12424-7}}.
* Kraas, Frauke, Surinder Aggarwal, Martin Coy, & Günter Mertins, eds. (2014). ''Megacities: Our Global Urban Future''. United Nations "International Year of Planet Earth" book series. Springer. {{ISBN|978-90-481-3417-5}}.
* {{cite book | last1=Latham | first1=Alan | last2=McCormack | first2=Derek | last3=McNamara | first3=Kim | last4=McNeill | first4=Donald | title=Key Concepts in Urban Geography | publisher=SAGE Publications Limited | publication-place=Thousand Oaks, CA | date=2009-01-14 | isbn=978-1-4129-3041-3}}
* Leach, William (1993). ''Land of Desire: Merchants, Power, and the Rise of a New American Culture''. New York: Vintage Books (Random House), 1994. {{ISBN|0-679-75411-3}}.
* Levy, John M. (2017). ''Contemporary Urban Planning''. 11th ed. New York: Routledge (Taylor & Francis).
* Magnusson, Warren. ''Politics of Urbanism: Seeing like a city''. London & New York: Routledge, 2011. {{ISBN|978-0-203-80889-4}}.
* Marshall, John U. (1989). ''The Structure of Urban Systems''. University of Toronto Press. {{ISBN|978-0-8020-6735-7}}.
* Marzluff, John M., Eric Schulenberger, Wilfried Endlicher, Marina Alberti, Gordon Bradley, Clre Ryan, Craig ZumBrunne, & Ute Simon (2008). ''Urban Ecology: An International Perspective on the Interaction Between Humans and Nature''. New York: Springer Science+Business Media. {{ISBN|978-0-387-73412-5}}.
* McQuillan, Eugene. ''The Law of Municipal Corporations'', 3rd ed. 1987 revised volume by Charles R.P. Keating, Esq. Wilmette, Illinois: Callaghan & Company.
* [[Sibyl Moholy-Nagy|Moholy-Nagy, Sibyl]] (1968). ''Matrix of Man: An Illustrated History of Urban Environment.'' New York: Frederick A Praeger. {{ISBN|978-1-315-61940-8}}
* [[Lewis Mumford|Mumford, Lewis]] (1961). ''[[The City in History|The City in History: Its Origins, Its Transformations, and Its Prospects]]''. New York: Harcourt, Brace & World.
* {{Cite book|last=O'Flaherty|first=Brendan|year=2005|title=City Economics|place=Cambridge Massachusetts|publisher=[[Harvard University Press]]|isbn=978-0-674-01918-8}}
* {{Cite book|last=Pacione|first=Michael|year=2001|title=The City: Critical Concepts in The Social Sciences|place=New York|publisher=[[Routledge]]|isbn=978-0-415-25270-6}}
* Paddison, Ronan, ed. (2001). ''Handbook of Urban Studies''. London; Thousand Oaks, California; and New Delhi: Sage Publications. {{ISBN|0-8039-7695-X}}.
* {{Cite book|last=Room|first=Adrian|title=An Alphabetical Guide to the Language of Name Studies|year=1996|location=Lanham and London|publisher=The Scarecrow Press|isbn=978-0-8108-3169-8|url=https://books.google.com/books?id=XEtiAAAAMAAJ}}
* [[Witold Rybczynski|Rybczynski, W.]], ''City Life: Urban Expectations in a New World'', (1995)
* Smith, Michael E. (2002) [http://www.public.asu.edu/~mesmith9/1-CompleteSet/MES-02-EarlyCities.pdf ''The Earliest Cities. In Urban Life: Readings in Urban Anthropology, edited by George Gmelch and Walter Zenner''], pp.&nbsp;3–19. 4th ed. Waveland Press, Prospect Heights, IL.
* [[Aidan Southall|Southall, Aidan]] (1998). ''The City in Time and Space''. Cambridge University Press. {{ISBN|0-521-46211-8}}
* Wellman, Kath & Marcus Spiller, eds. (2012). ''Urban Infrastructure: Finance and Management''. Chichester, UK: Wiley-Blackwell. {{ISBN|978-0-470-67218-1}}.
{{refend}}

===Further reading===
{{refbegin}}
* {{cite book |last=Berger |first=A.S. |title=The City: Urban Communities and Their Problems |publisher=Brown |year=1978 |isbn=978-0-697-07555-0 |url=https://books.google.com/books?id=INcgTPo-U1cC}}
* Chandler, T. ''Four Thousand Years of Urban Growth: An Historical Census''. Lewiston, NY: [[Edwin Mellen Press]], 1987.
* [[Patrick Geddes|Geddes, Patrick]], ''City Development'' (1904)
* {{cite triumph}}
* {{cite book |last=Kemp |first=Roger L. |title=Managing America's Cities: A Handbook for Local Government Productivity |publisher=McFarland |date=2007 |isbn=978-0-7864-3151-9}}
* {{cite book |last=Kemp |first=Roger L. |title=How American Governments Work: A Handbook of City, County, Regional, State, and Federal Operations |publisher=McFarland |date=2007-03-16 |isbn=978-0-7864-3152-6}}
* {{cite book |last=Kemp |first=Roger L. |title=Town and Gown Relations: A Handbook of Best Practices |publisher=McFarland |publication-place=Jefferson, NC London |date=2013-03-07 |isbn=978-0-7864-6399-2}}
* {{cite book |last=Monti |first=Daniel |title=The American City: A Social and Cultural History |publisher=Wiley-Blackwell |publication-place=Malden, Mass. |date=1999-10-29 |isbn=978-1-55786-918-0}}
* {{cite book |last=Reader |first=John |year=2005 |title=Cities |publisher=Vintage |location=New York}}
* Robson, W.A., and Regan, D.E., ed., ''Great Cities of the World'', (3d ed., 2 vol., 1972)
* {{cite book |last=Smethurst |first=P. |title=The Bicycle — Towards a Global History |publisher=Springer |date=2015-05-22 |isbn=978-1-137-49951-6}}
* Thernstrom, S., and Sennett, R., ed., ''Nineteenth-Century Cities'' (1969)
* [[Arnold J. Toynbee|Toynbee, Arnold J.]] (ed), ''Cities of Destiny'', New York: [[McGraw-Hill]], 1967. Pan historical/geographical essays, many images. Starts with "Athens", ends with "The Coming World City-Ecumenopolis".
* [[Max Weber|Weber, Max]], ''[[The City (Weber book)|The City]]'', 1921. (tr. 1958)
{{refend}}

==External links==
{{wiktionary|city|urban|metropolis}}
{{Sister project links|commons=Category:Cities|wikt=no|s=Cities}}
* [https://web.archive.org/web/20170710184532/https://esa.un.org/unpd/wup/index.htm World Urbanization Prospects], Website of the United Nations Population Division (archived 10 July 2017)
* [http://data.worldbank.org/indicator/SP.URB.TOTL.IN.ZS Urban population (% of total)] – World Bank website based on UN data.
* [https://www.statista.com/statistics/270860/urbanization-by-continent/ Degree of urbanization (percentage of urban population in total population) by continent in 2016] – [[Statista]], based on [[Population Reference Bureau]] data.

{{City topics|state=expanded}}
{{Land-use planning}}
{{Terms for types of administrative territorial entities}}
{{Authority control}}

[[Category:Cities]]
[[Category:Populated places by type]]
[[Category:Types of populated places]]
[[Category:Urban geography]]