Geography
London covers about 45 km along the navigable river Thames and is an average of 15 metres above sea level. London emerged from a settlement on the northern shore of today’s City of London. The London Bridge was until 1739 the only bridge over the river.
For this reason there is the larger part of the town north of the river. With the construction of additional bridges in the 18th Century and the construction of railways in the 19th Century began, the city extended in all directions. The landscape is flat to slightly wavy, allowing the unimpeded growth benefited.
The Thames was in earlier times much wider and shallower than it is today. It is now almost entirely limited by dams and most tributaries flowing underground. The tides of the North Sea “in London still clearly apparent, the city is therefore by floods and storm surges at risk. At Woolwich – located east of Greenwich – was in the 1970s the Thames Barrier built to curb this threat.
The geographical coordinates of the city centre near Trafalgar Square are 51.30 degrees north latitude and 0.08 degrees west longitude. The Royal Observatory, the Royal Greenwich Observatory in Greenwich, was the well-known prime meridian. He is the starting point for the longitudes and hence the time zones.
