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 surviving fragments of the Wall in Berlin and elsewhere around the world are generally pieces of the fourth-generation Wall. The layout came to resemble the inner German border in most technical aspects, except that the Berlin Wall had no landmines nor spring-guns. Maintenance was performed on the outside of the wall by personnel who accessed the area outside it either via ladders or via hidden doors within the wall. These doors could not be opened by a single person, needing two separate keys in two separate keyholes to unlock. As was the case with the inner German border, an unfortified