S2 (Berlin)
…the Berliner Verkehrsbetriebe (BVG) took over the S-Bahn network from the East German Deutsche Reichsbahn in West Berlin: the S2 initially ran between Lichtenrade and Anhalter Bahnhof, before being extended northwards to Gesundbrunnen on 1 May 1984, and Frohnau on 1 October 1984. In 1990, the S1 replaced the S2…