Since the fourteenth century, according to the records, the rock beneath Nuremberg Castle has been riddled with vaults and passageways with a total area of about 25,000 square meters.
These are not natural caves; they were laboriously hammered and chiseled by hand out of the native rock. Because of their consistent cool temperature, these cellars – going as far as four stories down – were ideal for making and storing beer.
Walkable passageways in the stone also served as a water supply system.
The extensive system of vaults and galleries under the Castle and the northern part of the Old Town was ventilated by an ingeniously simple trick: Strategically placed air shafts acted as a passive fresh air circulation system that worked superbly for centuries.