East London Line
The East London line is a London Overground line which runs north to south through the East End and Docklands areas of London. Originally part of the London Underground, the line closed as part of the £1 billion East London line extension in December 2007; a limited service was introduced on 27 April 2010 and full service commenced on 23 May 2010. Phase 2 which will link the line to the inner South London Line is due to be completed prior to the 2012 Summer Olympics.
The line which was built by the East London Railway Company reused the Thames Tunnel which had originally been intended for horse-drawn carriages. The line opened in 1869, it became part of the London Underground network in 1933 (coloured orange on the Tube map) before its conversion to overground operation in 2010.