The Cergowa and Kilanowska Mountains include the greatest assemblage of fissure caves in the Flysch Carpathians.

Such caves, in contrast to karstic caves, are formed in rock fissuring during landslides. On the Kilanowska Mountain, 60 landslide caves were already documented and new are still discovered. The "Słowiańska-Drwali" cave is the largest one.

With its over 500 m long passages , it is also the longest cave in the Flysch Carpathians. These caves are typified by an interesting feature – dynamics. Both gradual and rapid landslide movements result in the compression or formation of caves and changes in their passages.

In some of them, ice retains for most of the year. Entering such caves requires specialist cave equipment.