London Underground Fourteen Underground stations are outside Greater London, of which five (Amersham, Chalfont & Latimer, Chesham, and Chorleywood on the Metropolitan line, and Epping on the Central line), are beyond the M25 London Orbital motorway. Of the 32 London boroughs, six (Bexley, Bromley, Croydon, Kingston, Lewisham and Sutton) are not served by the Underground network, while Hackney has Old Street and Manor House only just inside its boundaries. Lewisham used to be served by the East London line (stations at New Cross and New Cross Gate). The line and the stations were transferred to the London Overground network in 2010. London
London Underground infrastructure London Overground – at New Cross and New Cross Gate. Of the boroughs that the Underground passes through, Hackney is served solely by Manor House station on the Piccadilly line in the very north-western edge of the borough. For the most part however some of the tube lines like the Central line skirt around the edge of the Hackney rather than going through it. Greenwich borough was unserved until North Greenwich station opened on the Jubilee line extension in 1999. The lines are electrified with a four-rail DC system: a conductor rail between the rails is energised at −210 V