In the Arenbergpark, located in Vienna's 3rd district, a massive concrete structure known as the G-Turm still stands, built during World War II as part of an anti-aircraft defense system. Constructed between December 1942 and October 1943, the G-Turm was one of two Flaktürme—massive, reinforced concrete towers—designed to protect the city from air raids. Alongside its twin, the L-Turm, the G-Turm also served as a civil air raid shelter and a military hospital. The walls and floors of these structures are exceptionally thick—up to 3.5 meters for the slabs and 2 meters for the walls—making them extremely difficult and expensive to dismantle. As a result, the G-Turm has remained largely untouched since the war. The G-Turm is currently used as a storage facility for the MAK (Museum für angewandte Kunst) in Vienna, while its twin, the L-Turm, remains completely empty. Both towers are massive in size, measuring 57 meters by 57 meters at ground level and rising 42 meters in height. They consist of eight floors, a firing platform, and a basement. These structures were not only built for defense but also incorporated functions like medical care and shelter, reflecting the multifaceted role of such facilities during wartime. A proposed project by the Austrian political party NEOS Wien in 2025 aims to transform the G-Turm into a "High Garden," a suspended garden that would bring greenery to the structure. However, the transformation of these towers has proven challenging. In 1990, an ambitious plan to convert the G-Turm into a residential building with a rooftop pool was abandoned due to local opposition. Since then, the structure has remained largely unchanged, its immense size and solid construction making it both indestructible and resistant to transformation. The G-Turm and L-Turm stand as remnants of a bygone era, frozen in time. While the G-Turm now serves a practical purpose for the MAK museum, the L-Turm remains an empty, imposing structure. Their presence in the Arenbergpark is a quiet reminder of the city’s wartime history and the complex legacy of its defensive architecture.