Only when winter is here, and the sky is an ashen blanket pulled over the city, do I notice the way a green film covers the trunks of the trees. Only in winter, when the gnarled branches of those trees reach into the pallid mist, and the dead leaves are slowly rotting into the earth, do I notice the thick slab jutting out of the ground of Humboldthain Park. I had walked here before and seen the monolith, but had dismissed it as another piece of neglected landscape architecture. But this concrete wall -- yes I can see that now -- is six feet thick. On its face are old windows, bricked shut, with steel hinges each the size of my fist.
There’s only one thing this could be. I search for a sign, a plaque, the remnants of some Denkmal, or monument, or anything that might tell me what it is. But there is nothing. Only this artificial hill, built from the detritus of bombed out buildings, its foundation the old wall of a Nazi bunker that couldn’t be destroyed.
Humbholdthain Park is one of Berlin’s green-space gems. It’s about 2,000 feet long, and almost as wide. A big Sommerbad, or outdoor swimming pool, is tucked in among the trees, along with an elegant rose garden, a small soccer court, and plenty of space. The trees are so dense that even in the leafless winter, one cannot see halfway across the park. And, unlike most of Berlin, the park actually has varied topography: A sort of valley in the park’s center is shielded from the urban bustle by two hills on the park’s edges. For the month or so when a few inches of snow covers the ground, kids on sleds rip down the smaller of the hills; runners do laps up and down the wide, smooth trail of the larger hill.
Like all of Berlin, Humboldthain has its ghosts. Jutting out of the top of the bigger of two hills is a pair of identical concrete blocks that look, even from up close, like overbuilt observation platforms. In fact, this is the northern edge of a massive, World War II bunker. Anti-aircraft guns shot at Allied planes as their bombs laid waste to the city. The bunkers themselves, which were built under Hitler’s orders at the beginning of the war, could hold thousands of civilians during an air raid.
While the towers – or Flakturm – couldn’t save the city, the bunkers turned out to be virtually impenetrable. The invading Russians, after their artillery failed to pierce the thick walls, had to skirt around them to reach the city’s center. After the war, the French occupied the Wedding district of Berlin, in which Humboldthain lies. Using something like 30 tons of TNT, they tried to demolish the bunkers. The north wall refused to collapse. So around the hulking structure the French piled up rubble – some from the bunker, some from a nearby church that had to be demolished, and some from surrounding neighborhoods, which, like all of Berlin, were bombed beyond recognition -- and built a hill.
Strangely enough, I learned most of this from an American TV show after I had lived near and walked in Humboldthain for several months. I did some more Internet research and uncovered a few more facts and wartime photographs. In recent years, people have become more familiar with the big bunker because a group has started giving tours of the “Berlin Underworld,” which includes a trip into the bunker’s innards (the outside walls, meanwhile, make for one of the only “natural” rock-climbing crags around). But the wall that I later found – clearly that of a second bunker -- is never mentioned anywhere. It’s almost as though everyone wishes it would just melt back into the earth, not a shred remaining, not even in our memories.
And that’s understandable. One need not go far in Berlin to find a monument reminding us of the atrocities committed here between 1933 and 1945. The Holocaust Memorial is the most visible and striking, but the Stumbling Blocks – shiny blocks embedded in the sidewalks engraved with details about Jews who were murdered or deported from the building or neighborhood – are equally painful. Dozens of other plaques, monuments and Denkmals are scattered across the city, each intended to remember the past so that we won’t let it happen again.
Just as a conscious effort has been made to remember and learn from those horrors, a parallel effort has been made to erase or simply ignore anything left over from that time that might be used to glorify the Third Reich or war in general. It seems to be a well-aimed jab at Albert Speer, the Nazi architect, and his theory of “ruin value.” He wanted to construct monstrosities that would continue to remind people of the Third Reich long after the Reich had collapsed and the structures had fallen down, much like Roman and Greek ruins still stand as reminders of ancient civilizations. Germans, to their credit, have done quite a bit to eliminate the ruins – not to mention the ruin value – of most of the work of Speer and his colleagues. Hitler’s bunker is under non-descript lot next to a Chinese restaurant, and until just a few years ago there weren't even signs marking its presence. Huge Flakturms in Tiergarten were successfully annihilated after the war, and are now gone.
Still, some ruins remain, like those in Humboldthain. They seem to be telling us that, no matter what we might do to forget, the landscape always remembers.
In his essay, “The Necessity for Ruins,” John Brinckerhoff Jackson writes: "A monument can be nothing more than a rough stone, a fragment of ruined wall as at Jerusalem, a tree, or a cross. Its sanctity is not a matter of beauty or of use or of age; it is venerated not as a work of art or as an antique, but as an echo from the remote past suddenly become present and actual."
Yes. Which is why, with this particular ruin, we can rejoice to see such beautiful graffiti on its face, and why we don’t cringe at the climbers’ bolts sticking out of the concrete next to the bricked up windows. And when I walk over those hills, the dog futilely chasing after rabbits and birds, I can’t help but think about what lies underneath, and can’t help but imagine a certain darkness seeping out of that wall, out of that rubble, and emanating up through the rotting leaves.