of a checkpoint. Its southern exit towards East Berlin was not reopened until 1 July 1990. Discussions on reopening all the U6 and U8 stations including the S-Bahn station , and had begun on 13 April 1990 without border controls. These took two months to clean up, removing all the dirt and refurbishing the interiors; all stations had been reopened on 1 July 1990 at 11 a.m., as East Berlin and East Germany had adopted the West German currency (DM), leaving the border checkpoints abandoned. On 2 July 1990, was the first ghost station on the to reopen. On 1 September 1990, and were opened following reconstruction works. On 12 December 1990, was reopened for West Berlin trains; a second platform for East Berlin trains allowing interchange followed on 5 August 1991. The very last ghost station to reopen was , which opened on 3 March 1992, following an extensive restoration of the entire North–South tunnel. In the following years, the city and German government put a great deal of effort into restoring and reunifying the and networks in Berlin. The U-Bahn system reached its pre-war status in 1995 with the reopening of on U1. The system reached a preliminary completion in 2002 (with the reopening of the ring), even though there are still disused sections of lines closed in the aftermath of the wall. Decisions on reopening of some of these sections are still to be made. There was a political promise made in the course of reunification that all S-Bahn lines and services shut down due to partition were to be restored - with federal funds if need be - but as of 2021 this is still not the case and some former services are seen to be as of lower importance than proposed entirely new construction. List of all Berlin ghost stations This list only includes those stations in East Berlin territory that western trains passed through without stopping. There were other stations on both sides of the wall that were closed during the division because those sections of track were not in use. Temporary checkpoints were set up for stations with access to East Berlin that were reopened before 1 July 1990. Checkpoints were no longer necessary for those reopened after that date when border checks were eliminated with the currency union between East and West Germany. New ghost stations after reunification In contrast with the