According to previous measurements of the debt more than 200 meters, and there is a possibility that is much longer.
The longest cave in Slavonia, debt, so far investigated, more than 200 meters, with a great bat habitat, geological, hydrological and biologically very interesting, is located in a wider area Grahovljani.
The cave is a great sit-bat habitat which, according to initial estimates, there are 3-4000. In addition, were found depigmented cave crayfish and some other critters.