Teufelsberg

Teufelsberg, meaning "Devil's Mountain" in German, is a man-made hill in Berlin’s Grunewald Forest, standing at 120.1 meters above sea level. It was created post-World War II from approximately 26 million cubic meters of rubble from bombed-out Berlin, covering an unfinished Nazi military-technical college designed by Albert Speer. The hill’s strategic height made it an ideal location for surveillance during the Cold War.

In the 1950s, the U.S. and British forces recognized Teufelsberg’s vantage point over East Berlin and the surrounding Warsaw Pact territory. Initially, mobile listening units were deployed in 1961 to intercept Soviet and East German communications. By 1963, a permanent facility, Field Station Berlin, was established, becoming one of the largest and most significant listening stations in the NSA’s global ECHELON network. The station featured five distinctive radomes housing 12-meter satellite antennas to capture radio waves, microwave links, and other signals. Contrary to some assumptions, it did not use radar but focused solely on signals intelligence (SIGINT). The facility operated 24/7, with personnel like linguist Lew McDaniel (1968–71) monitoring communications, aware of their vulnerability as a prime Soviet target.

The station was active until the fall of the Berlin Wall in 1989. After the Cold War, the U.S. and British forces abandoned it in 1991, removing all sensitive equipment. From 1991 to 1999, the site was briefly repurposed for civilian air traffic control, but it was abandoned again thereafter.