This needs no Introductory “Nazi Flak Tower”
One of the largest Bunkers in the world. its size is 75x75x38m, the walls are 3.5m thick, the roof is 5m. up to 25.000 people sought refuge during air raids in ww2.
after the war, it was rented out as apartements, since the rest of the city was bombed to rubble. plans of destroying it were scrapped, because the necessary explosions could also heavily affect the surrounding areas.
Today it houses a design studio, several music halls, and a club!