Banská Štiavnica is a town in central Slovakia, in the middle of an immense caldera created by the collapse of an ancient volcano. For its size, the caldera is known as Štiavnica Mountains. Banská Štiavnica has a population of more than 10,000. It is a completely preserved medieval town. Because of their historical value, the town and its surroundings were proclaimed by the UNESCO to be a World Heritage Site on December 11, 1993.
The heart of the town is the historical Trinity Square (Slovak: Troji?né námestie) dominated by a monumental plague column. The square is used for frequent cultural events and there is also a mineralogical museum. Two castles, the so called “old” one (Slovak: Starý zámok) and “new” one (Slovak: Nový zámok), have been transformed into museums. The open air mining museum offers a two kilometers long underground excursion in mines dated to the 17th century. Another ancient mine open to the public (Slovak: Glanzenberg) is even older. This mine, situated just under the center of the town, has attracted numerous famous visitors, from Emperor Joseph II to Prince Albert of Monaco.
The town is surrounded by ancient artificial mining water reservoirs called tajchy. Sixty reservoirs were built in the 15th through 18th centuries in order to provide energy for the booming mining industry. They are connected by a more than 100-kilometres long network of channels. These extraordinary historical monuments are now used mainly for recreation.