The olm is a part of the Proteidae family. Some people also call it the proteus or the cave salamander. It is an aquatic amphibian and the largest cave animal. Due to its pigmentation, an especially interesting subspecies is the black olm which only lives in the shallow Karst region of Bela krajina, in an area covering about 10km2. Due to its specific evolutionary adjustments, this is a species of extraordinary scientific and research relevance.