Salt mines.

Soledar is a city in Artemivsk municipality, Donetsk province of Ukraine. The name of the town stands for 'gift of salt' in Ukrainian. The town has a major tourist attraction: the underground galleries and chambers of salt mines, which are also used extensively for speleo (cave) treatment of asthma and other lung diseases.

The scale of the Soledar Salt Mines is vast. The mines have 125 miles of tunnel,are at a depth of 288m, and many of the chambers are 30 meters in height. The largest resembles a hangar of about 100 meters long and 40 meters width and 40 m height, and has accommodated soccer matches and the inflation of a hot air ballon.

The temperature underground is constant at 14–15 °C, 772 mm Hg air pressure and 60% humidity regardless of time of the year giving rise to claims of healing properties for lung conditions.

Many of the chambers are exquisitely decorated with carvings in the salt rock[. There are accommodation areas and even a church.

At a depth of 300 meters, you can find unique sanatorium “Salt Symphony” treating respiratory diseases.

You can even play soccer here.

In October 2004 the Donetsk Symphony Orchestra under direction of Austrian conductor Kurt Schmid gave a symphony concert in the main chamber, accompanied by Viennese Opera singer Victoria Lukyanets.

It's open for tours.