A former air-raid shelter built by forced laborers became the Banana Bunker during DDR days. Now it’s an exclusive art gallery – still monkey business.

Niederlehme's Treib- und Schmierstofflager 44, aka TSL 44, was a former oil and fuel storage facility used by Nazi Germany, then East Germany’s armed forces.

The "mouse bunker" animal-testing facility squats beside the Teltow Canal like a monstrous brutalist toad-tank, long blue turrets pointing every direction.

Lager Koralle was the forest bunker that controlled Germany’s feared U-boat fleet during World War II, central command for its marauding submarines.

A wartime bunker is all that’s left of the former Luna-Lager labor camp at Schönholzer Heide, now a grassy, pretty wild and pleasant 35-hectare park.