View source for Geography of London

{{Short description|none}} <!-- "none" is preferred when the title is sufficiently descriptive; see [[WP:SDNONE]] -->
{{See also|Greater London#Geography}}
{{Use dmy dates|date=January 2018}}
{{Use British English|date=October 2013}}
[[File:Greater london outline map bw.png|Outline of the London region|250px|right|thumb]]
[[London]] is the largest [[urban area]] and the capital city of the [[United Kingdom]]. It lies in the southeastern part of the island of [[Great Britain]]. The [[Greater London|London region]] covers {{convert|1579|km2|sqmi}}, and had a population of 8.982 million in 2019 and a population density of 5,596 people per square km in 2021. A larger area—the London Metropolitan Region or the London Metropolitan Agglomeration—covers {{convert|8382|km2|sqmi}} and had 12,653,500 people, at a density of 1,510 per square kilometre.<ref>{{cite web |url=http://www.dgcl.interieur.gouv.fr/sections/a_votre_service/lu_pour_vous/les_grandes_metropol/downloadFile/attachedFile/metropolislondres.pdf?nocache=1254397828.63 |title=Metropolis: 027 London, World Association of the Major Metropolises |access-date=3 May 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110427084411/http://www.dgcl.interieur.gouv.fr/sections/a_votre_service/lu_pour_vous/les_grandes_metropol/downloadFile/attachedFile/metropolislondres.pdf?nocache=1254397828.63 |archive-date=27 April 2011}}</ref>

London is a [[port]] on the [[Thames]] (see main article ''[[Port of London]]''), a navigable river. The river has had a major influence on the development of the city. London began on the Thames' north bank and for a long time the main focus of the city remained on the north side of the Thames. For many centuries [[London Bridge]] was the only bridge in or close to the city. When more bridges were built in the 18th century, the city expanded in all directions as the mostly flat or gently rolling countryside presented no obstacle to growth.

==360 degree panorama ==
{{wide image|London 360 from St Paul's Cathedral - Sept 2007.jpg|1400px|align-cap=center|''A panorama of modern London, taken from the Golden Gallery of Saint Paul's Cathedral''}}

==Rivers and canals==

===River Thames===
The [[River Thames]] is the main river of London, flowing west to east across the [[London Basin]]. The river cuts into the London basin through the [[Goring Gap]], draining parts of the [[Cotswolds]] and [[Vale of Aylesbury]] to the west. Similarly tributaries such as the [[River Mole, Surrey|Mole]] cut through the [[North Downs]] into the basin from the south. Further downstream the flow of the Thames is boosted by springs which open onto the chalky riverbed.

The Thames was once a much broader, shallower river than it is today. It has been extensively embanked. The Thames is tidal (the [[Tideway]]) up to [[Teddington Lock]], and London is vulnerable to flooding by [[storm surge]]s. The threat has increased over time due to a slow but continuous rise in high water level, caused by both the slow 'tilting' of Britain (up in the north and down in the south) caused by [[post-glacial rebound]] and the gradual rise in sea levels due to climate change. The [[Thames Barrier]] was constructed across the Thames at [[Woolwich]] in the 1970s to deal with this threat, but in early 2005 it was suggested that a {{convert|10|mi|km|spell=in|adj=mid|-long}} barrier further downstream might be required to deal with the flood risk in the future.<ref>{{cite web |url=http://news.bbc.co.uk/1/hi/england/london/4162905.stm |title=10-mile Thames flood barrier plan | access-date=2008-01-30|date=2005-01-01|publisher=BBC News}}</ref> Within London a considerable number of rivers and streams flow into the Thames, some large enough to have exerted a significant influence on the geography of the area. Many of the smaller London tributaries now flow [[Subterranean rivers of London|underground]].[[File:London by Sentinel-2.jpg|thumb|250x250px|Satellite image by Sentinel-2 satellite]]

===Left bank tributaries===

Larger left bank tributaries include the [[River Colne, Hertfordshire|Colne]], [[River Crane, London|Crane]], [[River Brent|Brent]], [[River Lea|Lea]] (tidal reach known as '[[Bow Creek (England)|Bow Creek]]'), [[River Roding|Roding]] (tidal reach known as '[[Barking Creek]]'), [[River Rom|Rom]] (lower reaches known as the Beam) and [[River Ingrebourne|Ingrebourne]]. There are many smaller, now often largely subterranean streams including [[Stamford Brook]], [[Counter's Creek]] (also known as 'Chelsea Creek'), [[River Westbourne|Westbourne]], [[Tyburn (stream)|Tyburn]], [[Tyburn Brook]], [[River Fleet|Fleet]] and [[Walbrook]]. Some of the tributaries are themselves large enough to have named tributary streams, for example the [[River Moselle (London)|Moselle]], [[Salmons Brook]] and [[Pymmes Brook]] that feed the Lea, and the [[Silk Stream]] and [[Dollis Brook]] that feed the Brent.

Larger rivers such as the Lea have influenced local geography in several ways:

*A river and its marshland formed a significant barrier to east–west movement: the Lea formed a natural boundary between the historic areas of [[Middlesex]] and [[Essex]].
*The valley of the Lea formed a transport route, including the river and later [[Lee Navigation]], as well as roads including the Roman [[Ermine Street]], the [[A1010 road (Great Britain)|Hertford Road (A1010)]] and the later [[Great Cambridge Road]] (A10) and A1055. The [[Lea Valley]] is also followed by two routes of what became the [[Great Eastern Railway]], and had important marshalling yards and locomotive works at [[Temple Mills]].
*The river provided power for numerous water mills, such as the [[Royal Small Arms Factory]] at Enfield and nearby [[Waltham Abbey Royal Gunpowder Mills]], [[Wright's Flour Mill]] (London's last surviving working mill) at [[Ponders End]] and  the [[Three Mills]] at Stratford.
*In the 19th century the lower Lea became an important area for the manufacture of chemicals, in part based on the supply of by-products such as sulphur and ammonia from the [[Gas Light and Coke Company]]'s works at Bow Common.
*In the 20th century the combination of transport, wide expanses of flat land and electricity from riverside and canalside plants such as [[Brimsdown Power Station|Brimsdown]], [[Hackney Power Station|Hackney]], Bow and [[West Ham Power Station|West Ham]] led to expansion of industries such as [[Enfield Rolling Mills]] and [[Enfield Cables Ltd|Enfield Cables]], [[Thorn Electrical Industries]], Belling, [[Glover and Main]], [[MK Electric]], [[Gestetner]], [[JA Prestwich Industries Ltd|JAP Industries]], etc.<ref name="Lewis">Jim Lewis 1999, ''London's Lea Valley'', Phillimore, {{ISBN|1-86077-100-9}}</ref> Much industry has now gone, to be replaced by warehousing and retail parks.

The valley also became very important for London's water supply, as the source of the water transported by the [[New River (London)|New River]] aqueduct, but also as the location for the [[Lee Valley Reservoir Chain]], stretching from Enfield through [[Tottenham]] and [[Walthamstow]].

A second significant corridor of canal, railways and industries was associated with the [[River Brent|Brent]], stretching from the Thames at [[Brentford]], through [[Isleworth]], [[Greenford]], [[Alperton]] and [[Park Royal]].

The [[River Colne, Hertfordshire|Colne]] (the historic boundary between Middlesex and [[Buckinghamshire]]) forms much of the western boundary of the county of Greater London.<ref>''Sheet 160 Windsor, Weybridge & Bracknell'', 1:25,000 Explorer series, Ordnance Survey, {{ISBN|0-319-21785-X}}</ref><ref>''Sheet 161 London South'', 1:25,000 Explorer series, Ordnance Survey, {{ISBN|0-319-21786-8}}</ref><ref>''Sheet 162 Greenwich & Gravesend'', 1:25,000 Explorer series, Ordnance Survey, {{ISBN|0-319-21780-9}}</ref><ref>''Sheet 173 London North'', 1:25,000 Explorer series, Ordnance Survey, {{ISBN|978-0-319-24164-6}}</ref><ref>''Sheet 174 Epping Forest & Lee Valley'', 1:25,000 Explorer series, Ordnance Survey, {{ISBN|0-319-21988-7}}</ref>

===Right-bank tributaries===

Significant tributaries include the [[River Mole, Surrey|Mole]], [[River Wandle|Wandle]], [[River Ravensbourne|Ravensbourne]] (tidal reach known as '[[Deptford Creek]]') with its tributary the [[River Quaggy|Quaggy]], and the [[Darent]] and its tributary the [[River Cray|Cray]] which together form part of the eastern boundary of Greater London. Smaller, some mainly subterranean tributaries include the [[Hogsmill River]], [[Beverley Brook]], [[River Neckinger|Neckinger]] and [[River Effra|Effra]].

The Wandle formed south London's nearest equivalent to the Lea Valley, with an industrial corridor stretching from the Thames at [[Wandsworth]] through [[London Borough of Merton|Merton]] and [[Mitcham]] to [[Beddington]] and [[Croydon]]. A smaller corridor followed the Ravensbourne from the Thames at [[Deptford Creek]] through [[Lewisham]], and many of the smaller rivers also once had mills.

===Canals===
A number of canals or canalised rivers have been constructed in the London area, mostly in the late 18th and early 19th centuries. These were originally for goods traffic, which has largely ceased. Within London the canals carried coal from the docks to many canal-side [[gas works]] and power stations (for example [[Brimsdown Power Station|Brimsdown]]), and timber to timber yards, furniture manufacturers etc. (for example in [[Edmonton, London|Edmonton]]). Although most of the canals still survive today, they are used primarily for leisure craft.

====North of the Thames====
Canal construction in the London area started with navigation works on the [[River Lee (England)|Lea]] and [[River Stort|Stort]] from 1424 onwards, leading to the [[River Lee Navigation]] and [[Bow Back Rivers]]. Initially used for transport of agricultural product from [[Hertfordshire]], this later became an important industrial waterway connecting the heavily industrialised Lea Valley with the [[Port of London|docks]]. A short-cut to the Thames avoiding the winding mouth of the Lea ([[Bow Creek (England)|Bow Creek]]) and closer to central London was provided by the [[Limehouse Cut]] (1760).

A connection from London to the [[English Midlands|Midlands]] had been provided by the [[Oxford Canal]] since 1790, but this required navigation up the upper Thames to [[Oxford]]. The completion of the [[Grand Junction Canal]] (later [[Grand Union Canal|Grand Union]]) from the Thames at [[Brentford]] (1798 onwards) provided a more convenient route. In 1801 an arm was opened from the Grand Junction at [[Hayes, Hillingdon|Hayes]] to a large basin at [[Paddington Basin|Paddington]]. This was later linked to the Thames at [[Limehouse]] (close to the Limehouse Cut) by the [[Regent's Canal]], completed in 1820. This in turn was linked to the Lea system by the [[Hertford Union Canal]] or Hackney Cut (1830). The Regent's Canal had many substantial basins ([[City Road Basin]], [[Kingsland Basin]], [[Battlebridge Basin]], [[St Pancras Basin]], [[Cumberland Basin (London)|Cumberland Basin]] etc.), originally lined with industries dependent on traffic from the docks.

The [[City Canal]] (1805) was built to provide a short-cut across the [[Isle of Dogs]]. This was later incorporated into the [[West India Docks]] and is no longer connected to the Thames at its upstream end. Other short canals connecting to the Thames included the [[Grosvenor Canal]] (1825) and the [[Kensington Canal]] (1828).

====South of the Thames====
The former [[Grand Surrey Canal]] (1807) was intended to run from the Thames at [[Rotherhithe]] to the industrial town of [[Mitcham]], but got no further than [[Camberwell]]. It closed with the [[Surrey Commercial Docks]] in 1970 and has been filled. The Grand Surrey Canal linked to the [[Croydon Canal]] (1809) which continued as far as [[West Croydon station|West Croydon]]; this closed in 1836.

Further afield a link from London to [[Bristol]] is provided by the [[Kennet & Avon Canal]] which connects the [[River Avon, Bristol|Avon]] at [[Bath, Somerset|Bath]] via the [[River Kennet]] to the Thames at [[Reading, Berkshire|Reading]]. [[Basingstoke]] could once be reached via the Thames, [[Wey Navigation]] and the [[Basingstoke Canal]]. The south coast at [[Littlehampton]] could be reached via the Thames, Wey and the [[Wey and Arun Canal]].

===Islands in the Thames===
:''Note: Only the largest islands are listed here. A longer list can be found in [[Islands in the River Thames]]''
* [[Chiswick Eyot]]
* [[Eel Pie Island]]
* [[Isle of Dogs]]
** [[Millwall]]
**[[Cubitt Town]]

==Topography==
''A list of the highest points can be found in [[List of highest points in London]]''

At the largest scale London lies within the bowl of the [[London Basin]], with most of the built-up area lying on the [[Tertiary period|Tertiary]] and younger sediments, and only a small part of south London ([[Sutton, London|Sutton]], [[Banstead]] and [[Croydon]]) lying on the chalk backslope of the [[North Downs]]. The centre of the basin is dominated by the modern valley of the Thames, which forms a level corridor running from west to east. The modern floodplain is around half a mile wide to the west of Greater London, expanding to two miles wide to the east. This is bordered by slightly higher and older terraces often extending several miles from the floodplain, for example in [[Hounslow]] and [[Southwark]]. Other significant river valleys include those of the Colne, Crane, Brent, Lea (with a floodplain more than a mile wide in places), Wandle and Ravensbourne, which run north and south towards the Thames.

There are a few notable hills in [[Greater London]], but none of them more than a few hundred feet high, and they have not impeded the development of the city in all directions. It is therefore very roughly circular.

===The hills in the City of London===
The hills in the [[City of London]], from west to east, [[Ludgate Hill]], [[Cornhill, London|Corn Hill]] and [[Tower Hill, London|Tower Hill]], are presumed to have influenced the precise siting of the early city, but they are very minor, and most of central London is almost flat. These hills are developed in  various gravel terrace deposits of the river Thames.

===North London===
To the north of the city a ridge capped by the mid-to-lower basin's residual sands known as the [[Bagshot Beds|Bagshot formation]] forms high ground (in places around 130m) including [[Hampstead Heath]] and [[Highgate|Highgate Hill]]. The ridge continues briefly eastwards over the London clay to form [[Crouch Hill]] and [[Queen's Wood]]. Immediately south, fingers of the ridge run down towards [[Primrose Hill]] and [[Parliament Hill, London|Parliament Hill]]. This ridge is a surviving area of [[Tertiary period|Tertiary]] rocks younger than the London Clay, surrounded by former routes of the Thames where much younger deposits overlie the clay. Smaller outliers of such Tertiary high ground exist to the west of the main ridge especially relatively lowly [[Hanger Lane]]; the knoll [[Harrow on the Hill|Harrow Hill]], and smaller [[Horsendon Hill]] where the [[London Clay#Claygate Beds|Claygate Beds]] (the top of the London Clay formation) are capped by much younger gravels deposited by watercourses.

North of this ridge, between the valleys of the rivers Lea and Brent, lies a second ridge (a little under 100m), formed of much younger [[Pleistocene]] deposits. Running west from [[Muswell Hill]] to [[Church End, Finchley]] and north to [[Whetstone, London|Whetstone]], this is capped by glacial [[till]] marking the southern limit of glaciation. This overlies ''Dollis Hill Gravel'' marking the line of a former southern tributary of the Thames, when the Thames flowed further to the north than it does today, through the Vale of St Albans.<ref>{{cite journal |last1=Gibbard |first1=P L |title=Middle Pleistocene drainage in the Thames Valley |journal=Geological Magazine |date=January 1979 |volume=116 |issue=1|page=35 |doi=10.1017/S0016756800041984 |bibcode=1979GeoM..116...35G |s2cid=130787135 }}</ref> At its eastern end at [[Alexandra Palace]] the gravel forms the top of the ridge, as it does in smaller hills to the west including [[Dollis Hill]] itself.

Further north, ridges of Claygate Beds overlain by the pre-glacial ''[[Stanmore]] gravel'' form the slightly broken-up ''[[Grim's Dyke]] Ridge'': [[Mill Hill]], [[Totteridge]], [[Arkley]] and [[Monken Hadley]], [[Elstree]], and Stanmore and [[Harrow Weald]] Commons.

Much of east and northeast London lies on the modern floodplain of the Thames (spared from flood by the Thames barrier) or older terraces, a notable interruption being the remains of the artificial [[Beckton Gas Works#Beckton Alps|Beckton Alps]]. [[Pole Hill]] at [[Chingford]] and Lippitts Hill near [[Gilwell Park]] are capped by small outliers of Claygate Beds, while the higher parts of [[Epping Forest]] such as High Beach are Claygate and Bagshot beds with later gravels.<ref name=Ellison>Ellison R.A. et al. 2004, ''Geology of London: Special Memoir for 1:50,000 Geological sheets 256 (North London), 257 (Romford), 270 (South London) and 271 (Dartford) (England and Wales)'', British Geological Survey, Keyworth, {{ISBN|0-85272-478-0}}</ref><ref>Sumbler M.G. (1996), ''London and the Thames Valley'', British Regional Geology series, British Geological Survey, {{ISBN|0-11-884522-5}}</ref><ref>''Sheet 255 Beaconsfield'', 1:50,000 Geology Series, British Geological Survey, Keyworth, 2005, {{ISBN|0-7518-3400-9}}</ref><ref>''Sheet 256 North London'', 1:50,000 Geology Series, British Geological Survey, Keyworth, 2006, {{ISBN|0-7518-3427-0}}</ref><ref>''Sheet 257 Romford'', 1:50,000 Geology Series, British Geological Survey, Keyworth, 1996, {{ISBN|0-7518-2971-4}}</ref>

===South London===
Faulting and folding brings the chalk close to the surface just south of the Thames in Lewisham and Greenwich. This has resulted in a notable ridge formed of [[Palaeocene]] deposits (the [[Lambeth Group]]), which includes [[Shooter's Hill]], [[Greenwich Park]] and [[Blackheath, London|Blackheath]]. West of the valley of the Ravensbourne, this ridge continues as [[Telegraph Hill, Lewisham|Telegraph Hill]], [[Nunhead]] and [[Honor Oak]], towards [[Denmark Hill]]. To the south [[Crystal Palace, London|Crystal Palace]] and [[Sydenham Hill]] lie on another outlier of Claygate beds.

In south-west London the lower terraces of the Thames of its west stop abruptly at a notable bluff cut into the London Clay against [[Richmond Hill, London|Richmond Hill]]. The higher ground across the east, save for the broad valley of the [[River Wandle|Wandle]] is capped across northern Wimbledon and the [[Norwood Ridge]] by Claygate Beds and older Thames gravels; the broad western part of this is dissected by the valley of [[Beverley Brook]], which separates [[Richmond Park]] from [[Wimbledon Common]].<ref name=Ellison /><ref>''Sheet 269 Windsor'', 1:50,000 Geology Series, British Geological Survey, Keyworth, 1999, {{ISBN|0-7518-3228-6}}</ref><ref>''Sheet 270 South London'', 1:50,000 Geology Series, British Geological Survey, Keyworth, 1998, {{ISBN|0-7518-3206-5}}</ref><ref>''Sheet 271 Dartford'', 1:50,000 Geology Series, British Geological Survey, Keyworth, 1998, {{ISBN|0-7518-3204-9}}</ref>

==Climate==
{{main|Climate of London}}
The climate of London is broadly similar to the rest of the UK, with warm summers, cool winters, no wet or dry season, and often moderate to strong winds. It is classed as a [[maritime climate|temperate maritime climate]] according to the [[Köppen climate classification]] system. In terms of the local climate profile, the temperature tends to increase towards the centre of the urban area, primarily because of the [[urban heat island]] effect, but also because London's topography results in the central area being the lowest part of the region in terms of altitude.

Daytime winter temperatures in London are around {{convert|8|C|F}}, but can vary from as high as {{convert|16|C|F}}, down to as low as {{convert|-7.4|C|F}}, as occurred during January 1987.<ref>{{cite web
|url=http://eca.knmi.nl/utils/monitordetail.php?seasonid=7&year=1987&indexid=TXn&stationid=1859
|title=January 1987 temperature.
|archive-url = https://web.archive.org/web/20160304095301/http://eca.knmi.nl/utils/monitordetail.php?seasonid=7&year=1987&indexid=TXn&stationid=1859|archive-date = 4 March 2016}}</ref> Night time temperatures hover a little above freezing, with frosts typically on 25-45 nights, depending on location. Absolute minimum temperatures range from {{convert|-10.0|C|F}} at St James Park, in central London down to {{convert|-16.1|C|F}} at Northolt during January 1962<ref>{{cite web|url=http://www.personal.dundee.ac.uk/~taharley/british_weather_in_january.htm |title=January 1962 weather |access-date=29 November 2012 |url-status=dead |archive-url=https://web.archive.org/web/20150903235843/http://www.personal.dundee.ac.uk/~taharley/british_weather_in_january.htm |archive-date=3 September 2015 |df=dmy }}</ref> - the lowest official temperature in the London area. More typically though {{convert|-12|C|F}} to {{convert|-13|C|F}} is the record minimum for most parts of London, as is shown by the [[Kew]], [[Heathrow]] and [[Hampstead]] figures. The lowest temperature to occur in recent years was {{convert|-14.2|C|F}} at Northolt during 2010.<ref>{{cite news
|url=https://www.theguardian.com/news/datablog/2010/dec/20/winter-weather-coldest-places-britain
|title=Winter weather: the coldest places in Britain
|access-date=2022-07-03
|location=London
|work=The Guardian
|first=Simon
|last=Rogers
|date=20 December 2010}}</ref>
During summer, daytime temperatures are typically around {{convert|23|C|F}}. Typically, according to 1981-2010 normals, the warmest day of the year at Heathrow will reach {{convert|31.6|C|F}},<ref>{{cite web
|url=http://eca.knmi.nl/utils/calcdetail.php?seasonid=0&periodid=1981-2010&indexid=TXx&stationid=1860
|title=Annual average warmest day
|access-date=2012-11-29}}</ref> and 26.4 days<ref>{{cite web
|url=http://eca.knmi.nl/utils/calcdetail.php?seasonid=0&periodid=1981-2010&indexid=SU&stationid=1860
|title=Average >25c days
|archive-url =https://web.archive.org/web/20160305195222/http://eca.knmi.nl/utils/calcdetail.php?seasonid=0&periodid=1981-2010&indexid=SU&stationid=1860|archive-date = 5 March 2016}}</ref> will attain a temperature of {{convert|25.1|C|F}} or above.  Kew's record high of {{convert|38.1|C|F}} is the highest temperature in the London area. In the summer of 2018, there was a hosepipe ban throughout London due to the high temperatures and lack of rain. London is vulnerable to [[climate change in the United Kingdom]], and there is increasing concern among [[hydrology|hydrological]] experts that London households may run out of water before 2050.<ref>{{cite news|url=https://www.independent.co.uk/climate-change/news/london-water-drought-climate-change-b2079811.html?amp|title=London could run out of water in 25 years as cities worldwide face rising risk of drought, report warns|author=Saphora Smith|newspaper=The Independent|date=16 May 2022|accessdate=5 June 2022|quote=London already receives about half the amount of rain that falls in New York City, and climate change will increase the frequency and intensity of droughts in the region}}</ref>

Sunshine tends to increase towards the west of the London area, with annual average at Heathrow and Kew in excess of 1,600 hours, at Northwood and Hampstead, in the 1,500-1,600 hour range, but at Greenwich, below 1,500 hours. The sunniest year on record at Heathrow was 2003, with, coincidentally, just over 2,003 hours of sunshine.<ref>{{cite web
|url=http://eca.knmi.nl/utils/monitordetail.php?seasonid=0&year=2003&indexid=SS&stationid=1860
|title=2003 Sunshine
|archive-url = https://web.archive.org/web/20110724160446/http://eca.knmi.nl/utils/monitordetail.php?seasonid=0&year=2003&indexid=SS&stationid=1860|archive-date = 24 July 2011}}</ref>

Heathrow - Airport Weather Station to the west of London, 
{{Heathrow Airport weatherbox}}

Kew - Weather station in the South West part of London, adjacent to the River Thames. 
{{Kew Gardens weatherbox}}

Hampstead - Weather Station in North London. The weather station enclosure is the most elevated of any in the London area, and as a result daytime temperatures are typically one degree lower than Heathrow, Kew, Northolt and Greenwich.
{{Hampstead weatherbox}}

Northolt - Airfield Weather Station in the North West of London. Temperature extremes range from {{convert|37.7|C|F}} in August 2003, down to {{convert|-16.1|C|F}} in January 1962.
{{Northolt weatherbox}}

Greenwich - Weather Station in South East London located near the river Thames.
{{Greenwich weatherbox}}

==See also==
{{Portal|London}}
*[[Agriculture in London]]

==References==
{{reflist|30em}}

{{DEFAULTSORT:Geography Of London}}
[[Category:Geography of London| ]]