U10 (Berlin U-Bahn)

The unbuilt U10 line, of the Berlin U-Bahn, was part of a planned "200-km-plan" extension of the Berlin U-Bahn from 1953–55, which was scrapped in 1977. It would have been a large-profile (Großprofil) metro line running from Falkenberg, in the northeastern part of the city, to Alexanderplatz, and down to Steglitz before terminating at Drakestraße in Lichterfelde. The designated letter name of the line was "F" until 1 July 1972, when it was changed to "Line 10". Because a number of tunnels and stations were constructed to accommodate the proposed line with elements visible at transfer stations and elsewhere, the line is popularly known as the "Phantomlinie" (Phantom line).