Attractiveness and uniqueness of cave formations, as well as rich archaeological, palaeontological and biospeleological site are the main characteristics of this natural monument and resource of the national importance. The cave is of indescribable, hidden beauty, where stalagmites, stalactites and helictites alternate with fragments of corals, aragonites and unique cave pillars, reminiscent of the ancient and Renaissance castles and colourful monuments. The cave is an outstanding speleological formation, the habitat of Cave bear (Ursus speleus), a distant ancestor of  Brown bear (Ursus arctos) more than 16,000 years ago.

‘Rastušje caves’ are a complex of 6 mutually joined caves, thus representing a karst enclave with all characteristic of karst terrain: caves, subterranean rivers , sinkholes and rock massifs. The entrance to the central cave is located on Hrnjo hill at 432 m above sea level and is located 80 m west of the Upper cave.

The caves are the biggest speleological formation in Republic of Srpska.  The whole cave is rich in different formations: the ceiling and walls are covered with stalactite and stalagmite formations and various calcite layers in combination with mineral solutions, among which  is especially prominent the so-called ‘Tiger’s skin’.

In terms of formations, this cave is one of the most beautiful ones in Bosnia and Herzegovina i.e. three caves of such type in Europe.