Berlin Hauptbahnhof fall of the Berlin Wall in 1989, city planners began work on a transport plan for reunified Berlin. One element of this became the "Pilzkonzept" (mushroom concept), in which a new north-south railway line intersecting the Stadtbahn was to be constructed. The name derived from the shape formed by the new line and existing lines, which vaguely resembles a mushroom. In June 1992 the federal government decided that the new station should be built on the site of Lehrter Bahnhof. While close to the centre of Berlin and government buildings, the area was still not heavily populated. The following year,
Embassy of the United States, Berlin gabled building was leased to the U.S. by the East Germans. The building no longer retains any of its original interior features. The exterior retains much of its original stone facade. With the fall of the Berlin wall and the unification of Berlin in 1989–1990, the U.S. State Department found itself with two main office facilities in one city: a Chancery in the former East Berlin, Mitte district (U.S. Mission to East Germany), and the Clay building in the Zehlendorf district of the former West Berlin (U.S. Mission Berlin). In accordance with the reality of a unified Berlin that was