Teufelsberg (German for Devil’s Mountain) is a man-made hill in Berlin, Germany, in the Grunewald locality of former West Berlin. It rises about 80 metres (260 ft) above the surrounding Teltow plateau and 120.1 m above the sea level, in the north of Berlin’s Grunewald Forest. It was named after the Teufelssee (i.e. Devil’s lake) in its southerly vicinity.
The US National Security Agency (NSA) built one of its largest listening stations atop 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.
In July 1961, Mobile Allied listening units began operations on Teufelsberg, having surveyed various other locales throughout West Berlin in a search for the best vantage point for listening to Soviet, East German, and other Warsaw Pact nations military traffic.
They found that operations from atop Teufelsberg offered 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). Construction of a permanent facility was begun in October 1963.
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.
During the NSA Operations some other curious things happened: It was noticed that during certain times the reception of the radio signals was better than during the rest of the year. The ‘culprit’ was found after a while: it was the Ferris wheel of the annual German-American Volksfest Festival on the Hüttenweg in Zehlendorf.
From then on, the Ferris wheel was left standing for some time after the festival was over. While there were rumors that the Americans had excavated a shaft down into the ruins beneath, that was never proven, and was likely based on reports that those who maintained equipment in one of the first enclosed antenna structures accessed the upper levels of the inflated dome via an airlock that led to a “tunnel” that was embedded in the structure’s central column.
Speculation as to what might have existed within the highly restricted area frequently gave rise to rather elaborate but false rumors; one theory stated that “the tunnel” was an underground escape route, another that it housed a submarine base.
In the 1990s, as Berlin experienced an economic boom after German reunification, a group of investors bought the former listening station area from the City of Berlin with the intention to build hotels and apartments. There was talk of preserving the listening station as a spy museum.
Berlin’s building boom produced a glut of buildings, however, and the Teufelsberg project became unprofitable. The construction project was then aborted. As of the early 2000s, there has been talk of the city buying back the hill. However, this is unlikely, as the area is encumbered with a mortgage of nearly 50 million dollars. Recently the site has been vandalized heavily since the company abandoned the project. The site is currently fenced off and manned by guards. Organised guided visits were possible until 1st September 2015.
Now an artists playground and commune, visits to view the graffiti art and gain access to the domes is still possible. Note that the site is not maintained to high safety standards (although better than when it was un-managed). The site and building have uneven surfaces, strewn with broken glass and debris. Accessing the main dome involves ascending a pitch dark stairwell in the center of the building. Entry is currently €7 payable at the main entrance gate.
Following the announcement of plans to raze the facility and reforest the hill, talk of preserving the facility resurfaced in 2009, spearheaded by the Field Station Berlin Veterans Group, which hopes to have the memorial named in honor of Major Arthur D. Nicholson, the last military Cold War casualty, the U.S. Military Liaison Mission tour officer who was shot and killed by a Russian sentry near Ludwigslust on March 24, 1985.
After no further construction was done after 2004, in 2006 the hilltop was categorized as forest in the land use plan of Berlin, thereby eliminating the possibility of building.