The speleologists went down into the largest karst failure in the world Bashny.Net

A hole in the ground with a width of 60 meters located in the forest and leads to the cave is located at a depth of 370 meters.
The natural wonder has attracted thousands of explorers from all over the planet. The failure is so deep that it clouds appear.



The cave is a popular base jumpers, but special experiments have shown that bird population in the ecosystem of failure began to contract, causing the access failure is severely limited.



For the first time in the failure was down 3 American in December 1967, since then, cavers from all over the world have visited those depths. The maximum depth of failure was almost five hundred meters, but the last hundreds of meters are available only in a few crevices.





I believe that the sinkhole appeared after the collapse of the roof of underground caves, which, in turn, was formed by water erosion along a fault line in the limestone.

Source: /users/413