opened on the West London line, between West Brompton and . East London line extension On 27 April 2010, the East London line became part of the London Overground network when the Phase 1 extension was completed. The former London Underground line was extended northwards, mostly along the former Broad Street viaduct of the North London line, to the re-opened , and southwards to and West Croydon. Operations began with a limited preview service between Dalston Junction and New Cross/New Cross Gate, with full operation between Dalston Junction and West Croydon/Crystal Palace on 23 May. On 28 February 2011, the line between Dalston Junction and Highbury & Islington was opened. In attendance were the Mayor of London and London Underground's Managing Director. TfL announced in November 2010 that ridership was ahead of forecast at 92,000 a day, and that patronage at Surrey Quays had "gone through the roof". The incorporation of the East London line into the Overground network has added substantial sections of line in tunnel, including the historic Thames Tunnel, the oldest tunnel under a navigable river in the world. A peculiarity is that at the London Overground runs below the London Underground (though there are other parts of the network where this occurs, e.g. the Watford Junction to Euston route between Kenton and South Kenton – shared with the Bakerloo line – passes under the Metropolitan line between Northwick Park and Preston Road). South London line extension The next addition opened on 9 December 2012, from to via the South London line, calling at , , , and . The extension uses an alignment between Surrey Quays and just north of that had been disused since 1911; new track was laid after some major civil engineering works. Passive provision has also been made for a new station at , to be constructed when funding becomes fully available. This was put on hold in 2009, although a suitable station 'foundation structure' has been built to facilitate completion in the future. Funding for the railway rebuilding project was secured in February 2009, including £64 million from the DfT and £15 million from TfL, and construction began in May 2011. The route passes over both and stations without stopping, and this lack of interchange stations was criticised by local politicians during the planning phase of the project. No stations are planned at these locations as the line is on high