Its first section opened in 1863,[1] making it the oldest underground metro system in the world – although approximately 55% of the current network is above ground,[2] as it generally runs on the surface in outlying suburbs.
The system is composed of 11 lines – Bakerloo, Central, Circle, District, Hammersmith & City, Jubilee, Metropolitan, Northern, Piccadilly, Victoria, and Waterloo & City – serving 272 stations.
Most of the system is north of the River Thames, with six of the London boroughs in the south of the city not served by the Underground.
Some stations at the north-eastern end of the Central line are in the Epping Forest district of Essex and some stations at the north-western end of the Metropolitan line are in the Three Rivers and Watford districts of Hertfordshire, and Buckinghamshire.
[4] Listed for each of the 272 stations are the lines serving it, local authority, the fare zone in which it is located, the date it and any earlier main line service opened, previous names and passenger usage statistics in millions per year.