Geography of London

Greater London covers an area of 609 square miles (1,579 km²). London used to be identified by its port on the Thames, which is a navigable river. The river had a major influence on the development of the city. London was founded on the north bank of the Thames and, for many centuries, there was only a single bridge, London Bridge. As a result, the main focus of the city was on the north side of the Thames.

When more bridges were built in the 18th century, the city expanded in all directions as the mostly flat or gently rolling countryside around the Thames floodplain presented no obstacle to growth. Today, there are a few hills in London, examples being Parliament Hill and Primrose Hill, they provide fine prospects of the city centre without significantly affecting the directions of the spread of the city and London is therefore roughly circular.

The Thames was once a much broader, shallower river with extensive marshlands. It has been extensively embanked, and many of its London tributaries now flow underground. The Thames is a tidal river, and London is vulnerable to flooding. The threat has increased over time due to a slow but continuous rise in high water level and the slow ’tilting’ of Britain (up in the north and down in the south) caused by post-glacial rebound. 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 ten-mile-long barrier further downstream might be required to deal with the flood risk in the future

Rivers and canals

The Thames was once a much broader shallower river than it is today. It has been extensively embanked, and many of its London tributaries now flow underground. The Fleet River is a good example of this. The Thames is a tidal river, and London is vulnerable to flooding by storm surges. 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 ten mile long barrier further downstream might be required to deal with the flood risk in the future .

Rivers
The River Thames
The River Brent
The River Cray
The River Lee (or River Lea)
The River Ravensbourne (tidal reach known as ‘Deptford Creek’)
The Wandle
The New River

Subterranean rivers

The Langbourne (dubious)
The Walbrook
The River Fleet
The Tyburn
The Tyburn Brook
The River Westbourne
Counter’s Creek
Stamford Brook
The River Neckinger
The River Effra

Canals

Grand Union Canal
Regent’s Canal
The River Lee Navigation
The Croydon Canal

Islands in the Thames

Note: Only the largest islands are listed here. A longer list can be found in the River Thames article
Canvey Island
Isle of Grain
Isle of Dogs
Millwall
Cubitt Town
Blackwall
Eel Pie Island

Hills

The hills in the City of London, from west to east, Ludgate Hill, Corn Hill and 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. 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.
Greenwich Hill
Hampstead Hill
Horsendon Hill
Ludgate Hill
Muswell Hill
Parliament Hill
Primrose Hill
Shooter’s Hill
Tower Hill
Tyburn Hill