Wieliczka Salt Mine, Kraków, Poland

Commercial mining was discontinued in 1996 due to low salt prices and mine flooding.
Touring
The Wieliczka salt mine reaches a depth of 327 meters and is over 300 km long. It features a 3.5-km touring route for visitors (less than 1% of the length of the mine's passages) that includes historic statues and mythical figures. The oldest sculptures were carved out of rock salt by miners; more recent figures have been fashioned by contemporary artists. Even the crystals of the chandeliers are made from rock salt that has been dissolved and reconstituted to achieve a clear, glass-like appearance. The rock salt is naturally gray in various shades, so that the carvings resemble unpolished granite rather than the white or crystalline look that many visitors expect. The carvings may appear white in the photos, but the actual carved figures are not white.