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,
Berlin Wall troops and workers had begun to tear up streets running alongside the border to make them impassable to most vehicles and to install barbed wire entanglements and fences along the around the three western sectors, and the that divided West and East Berlin. The date of 13 August became commonly referred to as Barbed Wire Sunday in Germany. The barrier was built inside East Berlin or East German territory to ensure that it did not encroach on West Berlin at any point. Generally, the Wall was only slightly inside East Berlin, but in a few places it was some distance