A huge high bunker from the Second World War with 1.5 meter thick reinforced concrete walls. On the top floor and on the roof is a two-story penthouse. Jutta and Klaus Greinert have been living in the spectacular penthouse apartment on top of the Mannheim bunker for almost 10 years.

The high bunker, with its accompanying low bunker, was built from 1940 to 1942. It was designed for 2,000 people. In an emergency, however, it provided shelter for up to 7,000 people. After the Second World War, American soldiers set up a base there and in 1972 the Bundeswehr took it over. In top secret, it stored equipment for reservists and planned procedures in the event of a nuclear war. After the end of the Cold War, the Bundeswehr left. Until the 1990s, the former air raid shelter then served only as a storage facility for diesel, food and drinking water supplies. For this purpose, the building had to be maintained in an elaborate and costly manner. Later, demolition of the concrete colossus was considered but rejected. After all, demolishing walls made of 1.5-meter-thick reinforced concrete is difficult and costly. In the meantime, the Mannheimer Hochbunker has been listed as a historical monument.

In 2000, the surrounding area was built over with residential buildings and an office building, and the underground bunker was converted into an underground parking garage. The bunker itself was difficult to market. Because of the reinforced concrete, it is virtually impossible to install windows. And conversions are hardly possible or quickly become immeasurably expensive. It was not until years later that a Mannheim restaurateur bought the massive structure and commissioned architect Felix Friedmann to build two habitable floors on the bunker roof. In 2005, this resulted in an exclusive penthouse apartment on the bunker roof with an elaborate breakthrough of the reinforced concrete ceiling into the top bunker floor.

When the air-raid shelter came up for sale again a few years later, Klaus Greinert learned about the unusual property. He is a former national field hockey player and Olympic participant. He is immediately fascinated by the building, as is his wife Jutta. In particular, the unique view of Mannheim and the entire region excites the two of them. At first, they consider whether their son could move in with his family. But the concrete colossus with the completely glazed floor on the roof does not seem suitable for the young family. Jutta and Klaus therefore decide to hand over their Mannheim villa to their son and henceforth reside themselves in and on the high bunker.

A film by Bastian Epple (editing and production), Enno Endlicher (camera), Lukas Steinki (camera) and Florian Wörz (sound). Production: EIKON Media GmbH, on behalf of SWR.

00:00 Living in the former bunker
00:40 Entrance with elevator
01:10 The high bunker
02:33 The low bunker
03:33 Oldtimer jeeps in the underground car park
04:15 History of the bunker
05:45 Living area on the roof
06:10 The office
06:37 Bedroom of Klaus
07:26 Bedroom of Jutta
08:28 The bathroom
09:23 Stairs and fitness area
10:35 Living area with kitchen
12:45 The view