This is the longest cave in the Dubrava part of the Western Rhodope mountains. Its entrance is oriented to the north and is situated 4.3 meters above the bed of the ravine, at 1107 meters altitude.
The cave has two storeys, and the floors branch 300 meters from the entrance. On the lower level of the cave there are the waters of Ribnovsko Dere, which come to the surface near Ribnovo in the form of karst springs. The water floor is a complex of corridors, small halls, waterfalls and thresholds.
The dry, upper floor begins with the Bats Gallery and only a few turns away from the gallery there is a hall with a small lake. After this room you can reach another one called Drujba, which is blocked with mud. At the southern end of the hall there is a great narrowing, which leads to a 7.5-meter threshold. Another gallery with three lakes with a depth of up to 1.5 meters follows.