We Can Be Happy Underground

One of the more interesting tours that we went on in Berlin was the Berlin Underworlds, a fantastic expedition into all the interesting remains of the various caverns, tunnels, tracks and shelters that lie underneath the city. Berlin, being built on a swamp, isn't anything like many other cities. For example, Rome is mostly built on top of Rome, whereas Berlin has one of the highest water tables in Europe which means you can only dig so deep. This also means that Berlin has very few tall buildings as the foundations can't go very deep and the few things that are underground are not very far down. Nevertheless there's still lots to see down there and our tour covered some 150 years of Berlin's underground history.
We began by taking a brisk walk from Gesundburnnen Station, down a large flight of stairs, across the platform, then up again into the daylight and across the road to an innocuous looking door on the side of the road. We descended down some much narrower stairs into a room with several benches and our guide gave us an overview of the whole tunnels and bunker systems telling us how they came to be built, their use in WWII as air raid shelters, and to their refitting for use as fallout shelters during the Cold War.
Our first stop was the past several radiation suits and through some more narrow twisting passages to see a part of the re-activated bunker from the Cold War period. Originally underneath the French quarter of Berlin after WWII this was turned into a fallout shelter after Stalin threatened to detonate a nuclear warhead over Berlin if the Allies didn't leave West Berlin. It turns out that this was somewhat of a crappy fallout shelter as the projected explosion of a 100 Kiloton nuclear device would have killed everyone in this particular shelter anyway.
Continuing on we saw more of the original tunnel system that was sued by the railways. This is what most of the bunkers and shelters in this location were before being used as air raid and fallout shelters. A decent amount of historic train memorabilia has preserved with the old station sign for Gesundbrunnen being donated by a household of students who were using it as a table.
The last part of the tour focused of the use of the tunnel systems as an air raid shelter during WWII. Again, it turns out to be security theatre as a direct hit on this shelter would have resulted in the top level or two of occupants being killed or badly injured.
A highly recommended tour, but unfortunately one in which photographs are not allowed.