Bunker an der Haltenhoffstraße, World War II air-raid shelter in Nordstadt, Hanover, Germany.

The Bunker an der Haltenhoffstraße is a World War II high-rise air-raid shelter in Hanover's Nordstadt, built in 1942 without a building permit and in breach of the spacing rules then in force. Its outer walls are 2.5 metres thick and the block measures 50 by 16 metres, with room for shelter-seekers on six levels during air-raid alarms. After the war, demolition charges blew 12-metre-high, four-metre-wide openings into the concrete, and the dismantling was soon abandoned.

This shelter was built in 1942 without official permits and served residents throughout the war as bombing intensified over Hanover. After 1945, its walls were significantly altered when large openings were cut through, changing its original purpose.

Locals call the structure a Schwarzbau, an illegal build, because it went up in 1942 without a permit and ignored the required distance rules. The 50 × 16 m block still stands as a document of wartime civil defence in the Nordstadt. A later plan to turn it into a media centre with studios and practice rooms for musicians was stopped by residents' objections in court.

The bunker stands in the Nordstadt district at Haltenhoffstraße; the structure is not open for interior visits, so the six levels can only be inferred from outside. The 12-metre-high, four-metre-wide openings blown into the 2.5-metre-thick walls are visible from the street and reveal the interior structure. A later plan to convert the building into a media centre with studios and practice rooms was stopped by a court after residents objected.

The bunker was built in 1942 without a building permit and in breach of the spacing rules then in force. After the war, demolition crews blasted large openings into the 2.5-metre-thick walls beside existing bullet holes, but stopped the work after a short time. Openings 12 metres high and four metres wide have gaped in the concrete block ever since.