The Salt Mines of Krakow were one of the biggest surprises of this trip and an amazing experience, too.  At one time this endeavor was worth more than gold and wars were fought over salt deposits.  This mine is so big it hosts full marathons under ground.  <https://www.visitwieliczkasaltmine.com>

The bldg that lets you into the mine and the elevator to bring you back up.  I took the 2d photo between the stairs going down to give a feel for the descent.

all the carvings were done by the miners and some are exquisite.  Enjoy.

A church under ground and all salt carving!