The Demänovská Ice Cave is situated in the entrance part of the Demänovská valley and includes parts of underground system of caves. It was created in blue-grey (guttenstein) Triassic calcites and has four floors. The little underground river Demänovka was a significant factor in its creation, what is proven by oval formations of cave tunnels with the rests of granite grits. The cave has three openings next to each other, at the same level on the western slope of the calcite reef Bašta, above the Kamenná chata (Stone Chalet). The entrance opening lies at the altitude of 740 m (90 m above the current flow of the river Demänovka). The upper floors have effloresced stalactite's and stalagmite's decoration, without ice, just the lowest one in the front part is glaciated. Visitors descend from the entrance to the lower floor - into the Medvedia corridor and from there into the Belov and Halašov Dome, into the Čierna Gallery and starting at the Dome of Pagods, they are returning back. On their return journey they can watch glaciated parts of Kmeťov (Kmeťo's) and Veľký (Big) Dome where the summer temperature never reaches 0°C. They can get from this part onto the surface through the new exit using the hairpin pathway. The total length of the cave is 1.7 km and just 540 m were opened for the public. Glaciating of the cave was facilitated by vertical character of its entrance and exit parts with surface openings in its highest places. In winter, colder air penetrates through mountain openings into the cave and descends to the lowest space (- 40 m) that cools down below 0°C. Water that leaks out through calcites freezes down and creates ice stalactites, stalagmites and split-level ice on the bottom. Other rooms that are located higher (Belov Dome, Halašov Dome, Čierna Gallery and Medvedia corridor) do not cool down and thus remain without ice formations. Their stalactite and stalagmite decoration has already “died out”.
In 1950 - 1952, unprofessional intervention into the microclimate regime of the cave during the works aiming to make the cave available for the public (rash digging out to its lowest space), changed the flow of the cold air in the cave back to the surface. This resulted in heating up of the ice decoration in the summer time. Nowadays the cave does not reach a degree of glaciating as it had before.
The Demänovská Ice Cave is one of the first known caves in the world. It is mentioned in the document of the Ostrihom's Chapter from December 5, 1299. The cave was explored for the first time in 1719 by Juraj Buchholtz jr., who made also its first lengthwise cross-section with marking of its all glaciated stalactite and stalagmite parts. Various scholars from all over the world sought after it. The cave was open to the public in 1880s thanks to the effort of the Liptovský department of the Karpatský club in the town of Liptovský Mikuláš.
People were visiting the cave with resinous torches, candles and paraffin lamps till 1924 when it became more famous thanks to the newly opened Demänovská jaskyňa slobody (Demänovská Cave of Freedom). After wooden stairs, pavements and electric lights were established, it was once more opened to the public in 1952.