London

The common name London may appoint several different geographical or administrative units, which can sometimes be confusing. 

The most common use refers to Greater London (Greater London), one of nine regional subdivisions of  England, formed of the territory under the control of the Greater London Authority and the Mayor of London. Greater London is considered a NUTS-1 within the European Union. It is this set of about 1600 km2 to 7.5 million people, which is commonly referred to when speaking of the British capital. Greater London is divided into two areas; Inner London and Outer London. Both areas are considered NUTS-2 regions. However, the Greater London is not officially a city, whose status is strictly defined in the UK, is awarded to a city by the British monarch on specific criteria. Before its creation in 1965, the territory was part of Greater London counties of Kent, Middlesex, Surrey, Essex and Hertfordshire. 



The City of London (City of London, abbreviated City, Square Mile or in reference to an area of ​​1 square mile), located in the heart of Greater London, is the historical definition of London. This is where the modern city was born and today is the oldest district of the capital. It's also a full-fledged district with special status. The city and the rest of London8 Grand London9 form two regions "Lieutenancy" (lieutenancy Areas) different.

Greater London is located in the South East of England, 50 miles west of the Thames Estuary and extends over an area of ​​1,579 km2, which puts the city at the thirty-seventh place of the most étendues11 cities. Elevations range from sea level up to 245 m in Biggin Hill, south of agglomération12. 

The river, which crosses the city from west to east, has had a major influence on the development of the city. London was originally founded on the north bank of the Thames and has arranged for several centuries, only one bridge, London Bridge (London Bridge). The main focus of the city is accordingly confined to this side of the Thames to the construction in the eighteenth century, a series of other bridges. The city was then extended in all directions, this expansion is hindered by any natural obstacle in a country almost devoid of relief, except for a few hills (Parliament Hill, Primrose Hill). 

The Thames was once wider and shallower than today. The river banks were heavily decorated, most tributaries were hijacked and are now underground, sometimes transformed into sewers (eg the Fleet River after which is named Fleet Street, the oldest street of journalists). The Thames is subject to the tide and is largely flood London. Flood threats also increase over time given the steady rise in the water level at high tide and slow tilt Britain (bearing north, lower in the south) caused by a isostatic rebound phenomenon. Dam, the Thames Barrier was built across the Thames at Woolwich in the 1970s, to overcome this threat. In 2005 however, it was suggested the construction of a dam of fifteen kilometers long further downstream to ward off future flooding.