Where: Bashkiria Nation­al Park, Bashko­r­tostan
Length: 9860 meters

The longest cave in the Urals. You can get into it only through a ver­ti­cal shaft 116 meters deep. Spele­ol­o­gists or trained trav­el­ers with climb­ing equip­ment descend here.

There are three lev­els inside the cave, with long flat sec­tions. Some­times the tun­nels expand into halls and gal­leries of impres­sive size. The largest room is the “Assem­bly Hall” grot­to. Its length is 130 meters and its width is about 10. It jus­ti­fies its name not only by its size, but also by the domed shape of the ceil­ing. Inside the grot­to you can see a small lake.