Okno Cave

The cave is known from time immemorial. It is situated on the right hand side of the Demänovská Valley in the Okno cliff at elevation of 915 m. The present length of cave spaces is 2,570 m with vertical span of 110 m.

The cave was first time described by M. Bel in 1723. New spaces were discovered by Prague scouts in 1921 and during surveys in 1923 - 1925.It is formed in the dark Middle Triassic limestones of the Krížna Nappe by erosion and corrosion of the Demänovka River.

The cave have quite rich flowstone fills, though partly damaged during surveys and by vandals. The cave has fluvial origin according to the character of spaces and occurrence of granite sediments. It represents the highest zone in the Demänovský Cave System. The temperature is between 5,8 –6,6°C and humidity has 88-96%.

The cave belongs among the oldest caves opened to tourists in Slovakia. The spaces were adapted by L. Povolný, as the owner of land, and during 1925 - 1926 he opened it to public. Archaeological findings from the younger Stone Age (Eneolith) were discovered in the cave.

Nine bat species were found in the cave. Regularly but only in less amount winter here the Greater Mouse-Eared Bat (Myotis myotis), Norhtern Bat (Eptesicus nilssonii) and Barbastelle (Barbastella barbastellus). The invertebrates include rare endemic form of troglophilic beetle Duvalius microphthalmus spelaeus, occurring only in the Demänovský karst. Palaeontological findings of fossile teeth of cave bear (Ursus spelaeus), brown bear (Ursus arctos) and remains of leopard (Panthera pardus) and lion (Panthera leo) were described from this cave.