Hochbunker

Hochbunker rises in Cologne as a stark, multi-storey cube with a flat roof and reinforced-concrete walls. Architect Wilhelm Riphahn designed the wartime air-raid shelter to protect thousands of civilians during bombing raids. Its broad, plain exterior gives little hint of the building’s unusual second purpose.

Riphahn incorporated ramps and floor connections so cars could later pass through with limited alterations. After the war, the lower levels became the Dom Garage, while upper floors held storage and civil-defence equipment. Twelve tall vertical openings were blasted through the walls during demilitarisation, changing the severe facade without removing its massive structure.

The roof reaches roughly one and a half metres in thickness, while some exterior walls approach two metres. Bright paint added colour during the nineteen seventies, before a glass facade brought the bunker into a modern office complex.