Stunning chapel located hundreds of feet below ground is made entirely out of salt

A 700-year-old mine probably doesn't conjure up images of health and wellness, but it should.

Deep inside the twisting tunnels of a 13th-century mine near Krakow, Poland, visitors will find chandeliers, statues and even a cathedral made entirely out of salt.

But perhaps most surprising is the existence of a full-fledged spa.

The Wieliczka Salt Mine, a UNESCO World Heritage Site, is known for its healing properties thanks to a unique microclimate that exists deep below the earth.

Beginning in the 19th century, underground mining chambers started being converted into a health resort. The main calling card for this unusual destination is its air. The spa website describes the mine atmosphere as 'free of pollution and allergens, rich in micronutrients, with constant temperature, high humidity, and free from harmful radiation.' These conditions make it ideal for people with asthma and other respiratory issues.

There are multiple spa packages to take advantage of the 'natural inhaler,' but perhaps the most interesting is the option to sleep over within caves to see how the body adjusts to 11 hours of pure breathing. And if you really, really like the concept of spending a weekend underground, you can force your loved ones to come by holding your wedding in the Chapel of St. King; a stunning salt hall located 101 meters underground that can hold up to 400 of your most adventurous friends.

Getting down to these relaxing chambers is a little less peaceful. Unless you are pregnant, elderly or otherwise unable to walk, visitors to the popular Polish site are encouraged to descend down hundreds of shallow, wrapping steps, deep down into the ancient chutes. Once your legs stop burning, you will follow a guide through several layers of tunnels.

But, be sure to pay attention. The salt has been continuously mined for hundreds of years. Tourists walk two miles with their guides, but that is only two percent of the passages' length. Your therapeutic trip could take a dark twist within seconds.