Teufelsberg Tour, Berlin

Teufelsberg, "Devil's Mountain", is a man-made hill in Berlin and it's named after the nearby Teufelssee, "Devil's Lake", which today is a favourite spot for Berliners to visit for nude sunbathing.  The site was supposed to be a Nazi military-technical college but it was never finished.  Following the war, about 26 million cubic metres of rubble of debris was brought here and in 20 years, and at 120,1 metres (394 feet) tall, it became the highest point in what used to be West Berlin.  During the Cold War, this was the perfect spot for a listening post.  It's even mentioned at the German Spy Museum.  

During the 1950s, SIGINT (signals intelligence) operations were conducted from the top floor of Templehof Airport.  There used to be four intelligence operations sites in West Berlin, with mobile operations units at Teufelsberg in 1961, but they were eventually consolidated at Teufelsberg once the permanent facility was built in the British sector at in late 1963.  

Officially Field Station Berlin, also known as FSB, Teufelsberg, Devil's Mountain, T-berg, the Hill, USM 620-Kilo, and das große Ohr (the big ear), was a radar station but people knew it was really a listening post.  The white tower and geodesic domes were visible for miles.  This allowed roughly 1500 American, and some British, military intelligence personal to listen 24x7 to communications traffic within a 500 km (310 mile) radius.  

With morse and non-morse code intercept operators, signals intelligence analysts, plus German and Russian crypto-linguists, Teufelsberg was one of the NSA's most important sites during the Cold War listening to and monitoring Soviet, East German, and other Warsaw Pact command and control systems.

Following the end of the Cold War, the site was closed.  Today it is abandoned, the antennas are gone and the insides of the buildings have been stripped.  Just like Iraklion Air Station, walking around there feels like a scene out of a zombie apocalypse movie.  Artists have come in there's some impressive graffiti all around.  

Here's a five minute video I found out on YouTube about Teufelsberg.

©Deutsche Welle

No one really knows what to do with the place.  Developers have come and gone.  In 2018 it was given protected status for its historical importance as a Cold War site which makes future development even more difficult.  

It's possible to visit the site on your own but I booked us a tour which allowed us to visit the site before other people were let in.  This added to the eerie vibe.  You can make your way up to the top for some pretty impressive views of the city.  We had a tour guide and she could tell us the basic history of the site and the current status.  But she had no real understanding of what type of work went on here when this was an active listening post.