Edward Snowden opened eyes to the significance of those huge radar spy domes you see on heavily guarded hilltops. What are they like close up or even inside?
You can find out by braving the wild boar that roam the Grunewald forest in Berlin and trek several un-signposted kilometres to Teufelsberg or Devil’s Mountain.
This is an artificial mount, 120 m high and very steep, which was built by the Allies from countless lorryloads of World War II rubble, dumped over the remains of Albert Speer’s military college. The National Security Agency then built tall towers and radomes on the top to spy on the East.
When the Cold War ended, the Americans left Teufelsberg, and property developers got permission to build luxury apartments with stunning views. But they gave up on the plan and the derelict site was sold to young German entrepreneurs who have now thrown it open to graffiti artists, a hippie commune and curious visitors.
But why did the developers give up?
In Cold War times computer mass storage could not cope with the vast amount of snoop data being collected. So everything was printed to paper. For security the paper then had to be burned on site. For fire safety the enormous storage and incinerator buildings were thick with asbestos.
Clearing the site of asbestos proved just too expensive, with the fear of crippling law suits if any dust leaked out and down into Berlin. The storage and incinerator buildings are now tightly sealed.
Fortunately the main radome tower was cleared to build a now graffiti-covered show flat, and is safe to enter, as long as you are careful not to fall off the edges or down the disused lift shafts.
So what is it like inside a radome? It’s huge, of course, like the inside of a giant football. The big surprise, though, is the acoustics. Being perfectly spherical the walls reflect and amplify sound so efficiently that a hand clap takes at least five seconds to decay.
How long before one of the avant garde rock groups that flourish in German gets the idea of recording there? Or perhaps they already have.