London Underground

The London Underground is a transit system that serves much of Greater London and some neighbouring areas. It is the world's oldest underground system, and is one of the largest in terms of route length. Services began on 10 January 1863 on the Metropolitan Railway; most of that initial route is now part of the Hammersmith & City Line. Despite its name, about 55% of the network is above ground. Popular local names include the Underground and, more colloquially, the Tube, in reference to the cylindrical shape of the system's deep-bore tunnels.

The Underground serves 275 stations and runs over 408 km (253 miles) of line. There are a number of closed London Underground stations. In 2005–2006, 971 million passengers used the Underground and for the first time ever in 2006–2007, over one billion passengers were recorded. As of March 2007, just over 3 million passengers use the Underground each day, with an average of 3.4 million passengers on weekdays.

Since 2003, the Underground has been part of Transport for London (TfL), which also administers numerous other transport-related functions, including the famous red double-decker buses. The former London Underground Limited was a subsidiary of London Regional Transport, a statutory corporation.