The Bunker

...or Sieg Highline!!!

We had actually had this name for a highline for quite some time, but we just couldn't find the right application for it, then it dawned upon us...

the bunker...

The upper line is over 40 meters long, about 15 meters high, and surprisingly scary and exposed. There are actually a number of possibilities to span shorter lines across this monster, but as yet only the two most obvious have been established. The upper line is called 'Sieg Highline!" and the lower is titled "Tiger Cage," because you have to climb over the huge 4 meter, spiked fence to get onto the line :)

A bump (the locals call it a “hill”) rises from the middle of the city in Humboldthain Park, near the Gesundbrunnen U-Bahn station. Here, you’ll find the Bunker, an apartment block sized anti-aircraft tower, or “Flakturm,” built circa 1941.

In 1940, Adolf Hitler ordered six such structures built to defend Berlin -- the headquarters and symbol of the Nazi party. He even drew the plans himself. By 1942, three -- including this one, the Humboldthain Bunker -- were finished and were used constantly until the end of the war. This structure is seemingly custom made for climbing, with its 60-foot north-facing wall, blocky bulges, and a 15-foot roof. It was also, alas, dead blank -- until Russian forces closed in on Berlin in the spring of 1945, shelling the wall from afar and spraying its expanse with bullets.

Perhaps nowhere else on Earth can you find a crag so inextricably linked with world history. For example, a favorite climb, Goblin (5.10c), boasts a forearm-sized hole at mid-height. Here, as your arm reaches into the Bunker’s cold bowels, you can’t help but be reminded that during the Berlin air raids, as many as 18,000 civilians huddled inside with only one hour of oxygen if the power was cut. (The interior walls were painted with white phosphorus -- itself extremely toxic -- which glowed during power outages.) In the last few weeks of the war, as the Russians closed in, Berliners amassed in these bunkers for weeks on end. Thousands committed suicide.

With its grim history, it’s fitting that the Bunker was the birthplace of climbing in Berlin. In the 1960s, Berlin alpinists trained here for “real” climbing, tackling the structure’s cracks with ladders, ropes, pitons, and other “old school” direct-aid techniques. Things progressed along these lines until the early 1980s, when some ambitious climbers installed such modern classics as Tausendsturz (5.11d) which means A Thousand Falls, now called the Wall of Voodoo, and West Berlin Wall (5.11b/c). The locals, however, were apparently having too much fun, because climbing was banned by the West Berlin Government from 1982 to 1987. In fact, the words “Klettern Verboten” are still partially visible, spray painted in huge black letters high on the cement.

Their government has never easily controlled Berliners, so hit-and-run bolting continued, with climbers piecing together the last great lines by linking bullet and bomb holes with chipped features. The ethic for the area was set at that time as follows: very hard technical climbing and very high first bolts. This, combined with the lack of a true warm-up, has imbued the Bunker, already said to be haunted by wartime ghosts, with a certain aura. The routes today, some 70 in all, range from 5.9 to 5.13a. (For a guidebook to the Bunker, visit


* The Humboldthain Bunker was the only bunker, out of three total in Berlin, not completely demolished by Allies at the war’s end. Its north wall is where you’ll find the majority of the climbs. A further 16 routs about 25 feet high - called Der Kleiner Bunker (The Small Bunker) - can be found on a small section of wall on the south side of the park.

*The Allies ordered displaced Berliners to heap war detritus around the base of the bunker to landscape for the future Humboldthain park and to seal the entrances. They moved 1.4 million tons of rubble.

*In its glory, the bunker stood over 200 feet high and was 100 feet long. Its reinforced-concrete walls measured 12 feet thick.

*128mm anti-aircraft guns, able to take down planes at 28,000 feet, protruded from ports around the Bunker’s perimeter, with lighter weapons manned on the roof. None of this prevented the Allies from dropping more than 100 million pounds of bombs on Berlin between 1943 and 1945.

*In the 1990s, seeing a renewed interest in the area by climbers and hikers, Berlin authorities removed dangerous tangles of broken metal and concrete, and sprayed liquid cement over many areas to solidify the mass.

*The Bunker is the largest bat sanctuary in Berlin. Regular tours of the Bunkers insides are stopped between October and April while the bats sleep. (taken from