Circle line (London Underground) the stations are shared with one or more of the three other sub-surface lines, namely the District, Hammersmith & City and Metropolitan lines. On the Circle and Hammersmith & City lines combined, over 114 million passenger journeys were recorded in 2011/12. The first section became operational in 1863 when the Metropolitan Railway opened the world's first underground line between Paddington and with wooden carriages and steam locomotives. The same year a select committee report recommended an "inner circle" of lines connecting the London railway termini, and the Metropolitan District Railway (commonly known as the District Railway) was formed to build
London Underground infrastructure although in some places, for example the Central line east of St Paul's station, tunnels are above each other. The running tunnels are on the right on the Victoria line between Warren Street and King's Cross St. Pancras, allowing cross-platform interchange with the Northern line between northbound and southbound trains at Euston. Six of the 32 London boroughs are not served by the Underground. All of these are south of the River Thames: Bexley, Bromley, Croydon, Kingston, Lewisham and Sutton. The borough of Lewisham used to be served by the Underground on the East London line – now part of