Dating from the1940s, the air raid shelter in Hamburg’s St. Pauli district has been reimagined as a „green mountain,” with expansive gardens covering the top of the wartime structure. Known as the Hochbunker, translated as ‘high bunker,’ the location has undergone a substantial restoration and refurbishment process introducing restaurants, event spaces, and a hotel, together with a rooftop urban park. The bunker has opened to the public on July 5, 2025, with the purpose of reconnecting the community with the iconic structure and its complex history.
Originally built under Adolf Hitler’s orders during World War II, this flak tower was constructed as a defense against aerial attacks. Completed in 1942, its concrete structure was designed to accommodate up to 18,000 individuals, with wide entrances for women with prams and children. Measuring 75 by 75 meters in width and 35 meters in height, the structure has remained a significant reminder of Germany's wartime past for over 80 years.
Because of the strength of the structure, demolition plans were quickly dismissed, as the process was likely to damage surrounding residential buildings. Since then, it has been used for various purposes. The recent restoration efforts were initiated by local residents' association Hilldegarden eV, who ensured the documentation of the bunker and initiated public participation in the transformation process, as community members interested in contributing to the memorial or urban gardening initiatives can connect with the non-profit group
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Paul Rudolph’s Brutalist Government Service Center in Boston Proposed for Mixed-Use Housing TransformationOne of the highlights of the project is its rooftop garden offering panoramic views of Hamburg and featuring a winding “mountain path.” A total of 80 sensors installed throughout the greenery aim to assess the impact of green roofs and facades on the microclimate. This sustainable irrigation system and planting design—incorporating 4,700 plants—aim to mitigate flooding and enhance biodiversity, positioning the bunker as a model for climate-resilient urban spaces. The bunker also sees the addition of a memorial for Nazi victims and facilitates spaces for local culture, art exhibitions, and events.
Due to it’s visually-striking presence, the project draws parallels with notable structures like New York’s High Line. Still, the recovery of its historical significance has been prioritized. Similar projects have gained traction across the world, such as EUROPARC’s redesign for the building housing the Parliament of the European in Brussels, Belgium, or the on-going proposals to reimagine Paul Rudolph’s Brutalist Government Service Center in Boston.
