World War II bunkers are opening up to peaceful projects. A way to reclaim a military heritage that is often abandoned.

The new Reverb by Hard Rock hotel will open at the end of May in the Feldstrasse bunker. A sinister concrete giant, it was one of a series of eight Fläkturme, anti-aircraft defense towers also installed in Berlin and Vienna. Erected in one hundred days in 1942 by 3,000 forced laborers, it sheltered up to 25,000 people.