This guided tour explores the Fichtebunker in Kreuzberg, a WWII air-raid shelter with six floors, 600 rooms and space for 6,000 people, built in 1941–1942 inside a disused gas holder to disguise it. It traces the building's history from industrialisation through the war to postwar use as refugee housing, a youth prison and a Cold War reserve, with exhibits and eyewitness accounts. The tour lasts about 90 minutes, involves mostly standing with few seats, and is not accessible without steps.

Details can change — check the event’s website before you go.