Klettern am Beton

Humboldthain Flank Towers are two historic flak towers at the top of a World War II air-raid shelter, a monstrous concrete structure from the early 1940s that offers a singular view of the north of Berlin.

The flak towers were built by personal order of Adolf Hitler in 1940. Following the first lethal air raids of the Royal Air Force on German cities, thousands of air-raid shelters were built all across the German Reich. This massive construction effort included building so-called flak towers, huge above-ground blockhouse towers equipped with anti-aircraft guns. Eight of these structures were built in Berlin, Hamburg, and Vienna. Flak is the abbreviation of Fliegerabwehrkanone, which literally translates to “aircraft defense cannon.”

These massive concrete structures are now a great location to climb offering climbing walls that are managed by the German Alpine Club.

After the climb, you'll have the opportunity to visit the interior of the tower. On this fascinating tour, we will be shown three of the seven floors of one of the biggest bunkers in the city. Here a dazzling underground landscape awaits – complete with dizzying views into the depths of the building. In addition, the guides will present in-depth information about the history of the structure and the still on-going project to clean it up. To date, members of the Berlin Underworlds Association have spent a total of over 8,000 hours removing over 1,400 cubic metres of rubble – and, in the process, have created ideal sleeping quarters for bats.

In the evening we can move in Friedrichshein, a vibrant neborhood in Berlin where you can also climb Der Kegel.

Der Kegel is over 18 metres high. Different types of climbing can be tried on the exterior of a former overhead hopper in Warschauer Straße in Friedrichshain. A combination of artificial handholds and the stone structure make climbing here a unique experience. And anyone who has trained long enough can also make it to the top of the Kegel: you will be rewarded here with a wonderful view and can write your name, the date and the route climbed in the summit log.

40 mins away from Berlin, there's another interesting bunker.

Koralle Lager was the code name of a military facility north of Bernau near Berlin, in which 1943-1945 the command center of the High Command of the Navy (OKM) and the radio control center for the submarine war was located.

In case you want to do some more exploration, we recommend visiting Teufelsberg in the evening.

Teufelsberg is a unique and fascinating landmark in Berlin that is worth exploring for those interested in history and architecture. It is a man-made hill standing 120 meters high, constructed from the rubble of World War II. Atop the hill, visitors can find the former US listening station, which was used during the Cold War to spy on East Germany and the Soviet Union. The station's architecture is striking, with its domed roofs and walls covered in colorful graffiti, making it a popular spot for urban explorers and photographers. Today, the site is open to the public and offers stunning panoramic views of Berlin from its observation deck. Visitors can also take guided tours of the station and learn about its history and significance during the Cold War. Teufelsberg is a unique and fascinating destination that offers a glimpse into Berlin's past and its continued evolution as a city. It also hosts some climbing spots that will be our main destination.