A patch of Woodland on the edge of the Südheide, where I live in Northern Germany. The area was heavily militarised, both during the war and after it. Not far from there are some larger bunkers that resemble old Aztec ruins among the trees. After the war, the nearby base was reduced in size and the new perimeter fence was built leaving these ruins outside for the forest to claim. The old East/West border is only a few kilometres down the road as well.