Pretty nice map. I like the feel and ambiance in it though :] But did encounter a glitch. On round 19, seems like dogs started to try and spawn in along side the zombies like Der Reise. But the dogs didn't work correctly, they were invisible and stuck in spawn room, and would just eventually die. You can knife the invisible body, but not shoot them. But knifing doesn't speed up the process of them dying.. It somehow effects the regular zombies spawning in, because after 10 or so zombies, the first dog tried to pop in, but all spawning stopped entirely asides from the infinite invisible dogs.
Anyways, nice map otherwise :]