
Since the 14th century, according to historic records, the rock beneath Nuremberg Castle has been riddled with cavernous vaults and passageways with an overall area of about 25,000 square metres.
These subterranean chambers are not, however, natural caves, but were laboriously excavated by hand out of the native rock, using hammers and chisels. Because of their constant cool temperatures, these sandstone cellars (in places, up to four stories deep) were ideally suited for the brewing and storage of beer.
Passageways cut into the aquaferous sandstone also served as a water supply system.
The method for ventilating these vast underground galleries underneath the northern part of the Old Town was ingeniously simple. For hundreds of years now, the automatic circulation of fresh air has been effectively insured by strategically placed pairs of ventilation shafts.