Editing City (section)

==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="Kaplan2004p155">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="Marshall1989p15">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="Latham2009p18" />

=== 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="Latham2009p18">{{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=1 November 2024 }}{{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="Smith2002">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>{{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="HugoEtAl2003" />

[[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>