The world's largest salt mine over 700 years old

The Wieliczka Salt Mine is located in southern Poland, about 16 km from the old city of Krakow. Wieliczka is one of the oldest salt mines and is a UNESCO World Heritage Site. The mine was exploited from the 13th century until 1996 and was the largest source of salt in Poland for many years before becoming a tourist destination. Over the past 700 years, 26 wells have been drilled, creating about 9 million cubic meters of void space in the Wieliczka mine, with the deepest point reaching 327 m.

The empty caves left after mining have been repaired over the years to become a "new world" where visitors can explore on foot at a depth of 137 m.

Source link: https://vnexpress.net/mo-muoi-hon-700-nam-tuoi-lon-nhat-the-gioi-4694435.html