Natural settings
The Jasovská Cave is formed in Middle Triassic grey Gutenstein dolomites and pale Steinalm limestones and dolomites of the Silica Nappe. The massif of the Jasov Rock is markedly disrupted by faults and numerous fissures, which condition the prevailing direction of passages and to great extent also the number of passages in the cave. The Jasovská Cave reaches the length of 2,811 m with vertical span of 55 meters.
The underground space were formed progressively in several development phases from the highest passages to the lowest parts of the cave in relation with the development of the Bodva River valley. Upper and some bottom parts of the cave with high meander passages and halls with ceiling troughs were formed by corrosive and erosive activities of ancient ponor waters of Bodva. The lower parts of the cave with domes, halls, wall notches and flat roofs were formed by more or less stagnant water. The lowest parts of the cave with flat roofs were formed by solution of limestone under conditions of slowly moving stagnant water.
The lowest parts of the cave including a part of the show path use to be flooded in consequence to water-table fluctuations. The lowest level of cave lake is 7 m below the surface Bodva River level, which doesn’t flow through the cave at present. An occassional flooding of the cave lower parts doesn’t correlate with Bodva River fluctuations.
Several parts of the cave are decorated with rich flowstone fill. Pagoda-like stalagmites, columns, flowstone waterfalls, shields, drums, straw stalactites and other forms are eye catching. Air temperature ranges between 8.8 and 9.4 ºC, and relative humidity between 90 and 98%.
Bones of cave bear (Ursus spelaeus) and cave hyena (Crocuta spelaea) were found in the cave as remains of ancient animals. Nowadays, the Jasovská Cave is a very important bat locality. By now, 18 bat species were found in the cave. They stay in the cave mainly in the winter season. The most abundant is the Greater Horseshoe Bat (Rhinolophus ferrumequinum) and Lesser Horseshoe Bat (Rhinolophus hipposideros). The cave is one of the most important wintering places of the Greater Horseshoe bats in Slovakia. A tiny palpigrade Eukoenenia spelaea represents the rare invertebrates.