Berliner Unterwelten

Last wednesday I went to Gesundbrunnen station, where Berliner Unterwelten has their office and starts their tours of a small part of Berlins underground heritage. I took the Tour 1: Dark Worlds, which explores a civilian bunker complex right there under the station. Its location prevented it from being blown up in the demilitarisation of Germany after the second world war and it offers an excellent impression of how thousands of civilians spent cramped, terrified nights during the bombing of the city. Tours happen in English as well, just check the calender. The tour guide offered us (about 15-20 people) a lot of information about the how and why of the bunker, about the war itself and how Germany copes with its history (he was Danish so he could offer a neutral account). Tours are 9 euro, which is well worth it for 90 minutes.
Other tours include a visit to a cold war bunker or to the partially demolished flak tower in the park right across the streat of the gesundbrunnen station. Check out the google maps view of the Volkspark Humboldthain. It's well worth a look on the outside as well, just go to the park and climb the hill. It's a pretty impressive view and you have a nice lookout over part of the city. Looking forward to take the tour exploring the innards of that tower as well!
Oh, you wonder why they built that bunker on the side of that hill and not, lets say, on top of it? That's because the hill is part of the flak tower. After the war it was blown up, but the building was so tough they only managed to destroy part of it and besides, the northern part of the building faces the railway lines. The resulting heap of rubble was covered with soil and now it looks just like a natural hill - until you reach the northern side.

There are lots of "rubble hills" all over Berlin, so it seems. Check out this wikipedia article about Teufelsberg. Got to visit that as well :)
After googling a bit, it turns out that - who else - the guys and gals from Berliner Unterwelten would very much like to check out what's buried under the Teufelsberg.
Turns out that a lot of nazi history is buried under heaps of rubble, either of parts of the building itself or of other buildings as well. Can't really blame everyone involved, from the Allied and Russian forces demilitarizing Berlin to the shocked citizens of Berlin, wanting to bury the remains of the nazi era under layers and layers of forgetting.