Röhrenbunker

Röhrenbunker lies beneath the lawn in front of Cologne’s Oberlandesgericht, built in 1911. A simple metal grate marks the entrance. Seventeen steps lead into a largely preserved air-raid shelter from 1942, where the M-shaped concrete structure occupies 135 square metres. The ceiling measures only 30 centimetres thick and lies just 30 centimetres beneath the grass.

Around 180 people could shelter here during air raids, packed into narrow underground passages. Explosions remained clearly audible inside. Two hand-operated ventilation systems, original toilets and a heating system show how the space functioned during wartime. A central emergency exit used sand, which flowed away after occupants broke through a wall when both entrances were blocked. That mechanism remains intact.

After serving as storage for court files until 1979, the bunker remained largely untouched until 2009. Old wartime light bulbs still survive among restored benches, personal belongings and shelter equipment. The Cologne Fortress Museum now presents the site through guided tours focused on civil defence and civilian experiences. This preserved tube bunker leaves one striking detail: a hidden wartime shelter sits beneath ordinary grass beside the courthouse.