Feldstraße Bunker in Hamburg, Germany

The Feldstraße Bunker in Hamburg, Germany, is a unique building that combines Brutalist concrete with lush greenery. The bunker was originally built in 1942 as part of the eight Flak towers constructed during World War II to defend major German cities. The towers were designed to provide anti-aircraft defense and could also serve as air raid bunkers, with the capacity to hold up to 10,000 people. Despite their impenetrable 3.5-meter-thick walls, the Flak towers did not prevent cities from being bombed by the Allies. After the war, the Feldstraße Bunker was used as emergency housing and later as temporary housing for victims of domestic abuse. In the 1990s, the bunker was repurposed as a center for media businesses, including a concert hall and nightclub. The idea of "greening" the bunker by adding plants on the exterior was first proposed in 1992, but it wasn't until the 2010s that the project gained momentum. The "green bunker" was finally completed in 2024, featuring a hotel, restaurants, event hall, fitness club, rooftop garden, and panoramic staircase. The building's unique design has been met with both praise and criticism, with some criticizing the scaling back of the greenery due to fire codes. The "green bunker" is now open to the public, offering a unique blend of history, architecture, and natural beauty.