The Wieliczka Salt Mine, located in the town of Wieliczka, is within Poland’s Kraków metropolitan area. It had been until 2007 in continuous operation, producing table salt, since the 13th century. It was one of the world’s oldest operating salt mines.

The mine reaches down to a depth of 327 meters (1000 feet) and is over 300 km (180 miles) long.
Deep inside is a huge hand-carved auditorium with statues and carvings.

The room has been used for meetings, concerts and for religious services; some people call the room a cathedral.
It has an altar and shrine to Mary at the far end.