The photographer and physicist Werner Lorke illuminates the changing history of a former bomb shelter and hotel which was in use under the Market Square in Stuttgart from 1945 until 1995. The windowless rooms remain to this day with their wallpapered walls and 60's and 70's era lamp fixtures. Through the years wildly growing mould colonies have covered the walls and remaining furnishings. Following the various stages of decomposition, unusual and strange patterns have arisen. Large format photographs provide a view into a bizarre world. The book does not rest solely on the charm of the morbid. The historic, architectural, and urban planning contexts which were allowed by the construction of the bunker biotope are communicated along with the microbiological conditions.