The Wieliczka salt-mine was opened in the 13th century and had produced table salt until 2007. When it was up and running in 2007 it was the oldest producing salt-mine in the world.
The pictures are from the cathedral that the miners had built. Everything from the flooring to the chandeliers are made of salt. It was a well paid, but dangerous job, and the miners would spend their days beneath the surface of the earth, sometimes not returning to the air for days (the horses would remain under the earth for seven years at a time). To the miners each day was a blessing to be alive and they built this cathedral along with images from the bible for a place to pray beneath the depths. The mine reaches the depth of 327 meters (1,073 feet). On the tourist route we only go to 135 meters.