London Underground

The London Underground is an underground railway system - also known as a rapid transit system - that serves a large part of Greater London, United Kingdom and some neighbouring areas. It is the world's oldest underground system, and is one of the longest in terms of route length. Services began on 10th January 1863 on the Metropolitan Railway; most of the 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.
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