The Wieliczka Salt Mine is a historic salt mine located in Wieliczka, Poland. It has been continuously operating since the Middle Ages. In 1978, it was inscribed as a UNESCO World Heritage Site for its cultural and natural value. The mine contains over 300 km of passages and chambers, some reaching depths of over 300 meters. It is renowned for its carved statues, chapels, and other architectural elements hollowed out of salt rock. Over a million tourists visit annually to see its underground attractions.