Wednesday, Aug 19, 2020, 2:27 pm

By:Tony Williams

#2 Wieliczka Salt Mine - Krakow, Poland

Existing since the Middle Ages, the Wieliczka Salt Mine is an extravagant underground place that has to be seen to believe. In continuous operation, sculptures have been engraved into the Miocene salt, with a cathedral ceiling and floor made from salt crystals. with over a million visitors per year, the salt mine is a popular attraction.