The Wieliczka Salt Mine was built in the 13th century. As one of the world's oldest salt mines it's still in operation. The mine's attractions include dozens of statues, three chapels and an entire cathedral that has been carved out of the rock salt by the miners. Even the crystals of the chandeliers are made from rock salt that has been dissolved and reconstituted to achieve a clear, glass-like appearance.
Wieliczka reaches a depth of 327 metres and is over 287 kilometres long. During the World War II, the shafts were used by the occupying Germans as an ad-hoc facility for various war-related industries. In 1978 the mine was placed on the original UNESCO list of the World Heritage Sites.