25 years after the fall of the Wall, Berlin's listening towers still draw visitors It is one of Berlin's most potent reminders of the Cold War. Built by the American National Security Agency in the 1960"s, the listening towers on 'Teufelsberg' in former West Berlin were used by the Allies to spy on the Soviet and the East German military. After the station was abandoned by the Allies following the fall of the Wall, the tattered towers were sold to investors who planned to build luxury hotels and apartments on top of the hill where they stand. But the project never took off and the site has been mostly used as a squat since. Now visitors to the site are more likely to see graffiti and the left-overs of an all-night rave party. First of all, it's a secret place, and people like secret places. They know that it was an important place but the details - they have no idea. So I think there is the mystique of a secret place, that's really the most important thing. And those who know something of the period - they find it interesting as well," says tour guide Christopher McLarren. Bob Beney and Collin Gregory were stationed at the British air base RAF Gatow near Teufelsberg. Each morning they would travel by bus from the airbase "up the hill" to work as intelligence officers at the listening station. It's their first time back since being stationed here. When I came here and I saw this for the first time it was quite amazing. It wouldn't be like a lost lover because it wasn't that sort of place. But it's really quite remarkable that, after 44 or 45 years, one would come back. It was quite something, quite something," says Bob, who worked there between 1968 and 1970. Collin was stationed there between 1968 and 1971: "It is sad to see the demise. Having said that, of course, we are so glad that it resulted with Germany's reunification. And so, I think we can honestly say that our small part, hopefully, played a part in German reunification and perhaps the end of the Cold War," he says. Though it lost its raison d"être after the fall of the Berlin Wall, Teufelsberg's listening station still offers a peek into the paranoia of a bygone era and continues to attract thousands of visitors each year.