The US National Security Agency (NSA) built one of its largest listening stations on top of the hill, rumored to be part of the global ECHELON intelligence gathering network. “The Hill”, as it was known colloquially by the many American soldiers who worked there around the clock and who commuted there from their quarters in the American Sector, was located in the British Sector. Prior to establishing the first permanent buildings there in the very late 1950s, Mobile Allied listening units had driven to various other locales throughout West Berlin hoping to gain the best vantage point for listening to Soviet, East German, and other Warsaw Pact nations military traffic. One such unit drove to the top of Teufelsberg and discovered a marked improvement in listening ability. This discovery eventually led to a large structure being built atop the hill, which would come to be run by the NSA (National Security Agency). At the request of US government, the ski lifts were removed because they allegedly disturbed the signals. The station continued to operate until the fall of East Germany and the Berlin Wall, but after that the station was closed and the equipment removed. The buildings and radar domes still remain in place.
Beelitz-Heilstätten, a district of the town, is home to a large hospital complex of about 60 buildings erected in 1898 and deigned by architect Heino Schmieden. Originally designed as a sanatorium, the complex from the beginning of World War I became a military hospital of the Imperial German Army. During October and November 1916, Adolf Hitler was treated at Beelitz-Heilstättenfor a leg wound at the Battle of the Somme. In 1945, Beelitz-Heilstätten was occupied by Soviet forces, and the complex remained a Soviet military hospital until 1995. In December 1990 Erich Honecker was admitted to Beelitz-Heilstätten after being forced to resign as the head of the East German government.