Natural settings
The cave represents morphologically the most varied part of the Demänovský Cave System. It is formed in the Middle Triassic dark-gray Gutenstein limestones of the Krížna Nappe along the tectonic faults by the ancient ponor flow of Demänovka and its side hanging ponor tributaries. The length is 8,126 m with elevation distance of 120 m.
The lower oval, river modeled passages of the cave represent four horizontal development levels (Marble Riverbed, Loamy Passage, Dry Passage, Ground Floor, Král’s Gallery). They are in places widened by collapses (Great and Spouting Dome, Pink Hall, Hell Dome). Steeply descending passages lead into cave levels in hanging positions, mostly from the place of present cave entrance and exit. Except for the smaller oval passages (Passage of Suffering, Virgin Passage, Bear’s Passage, Treasury) they include also bigger spaces (Sphere Dome, Parachute Abyss, Janosik’s Dome, Hviezdoslav’s Dome, Deep Dome). The Miraculous Halls, Magical Passage and Stone Vineyard have a fissure character. From among the flowstone fills, the water lilies and other lacustrine forms (sponge, coral, grapes forms) and also eccentric stalactites are unique. Mighty flowstone waterfalls and columns, sphaerolitic stalactites and many other forms of stalactites and stalagmites are captivating. A thick layer of white soft sinter – moonmilk can be found in the Great Dome.
The underground water course of Demänovka, which springs in the non-karst territory under the main ridge of the Low Tatras, flows through the cave. It sinks underground in Lúčky and springs again through the Vyvieranie Cave northerly from the Demänovská Cave of Liberty. The Great Lake is 52 m long, 5 to 12 m wide and more than 7 m deep. Air temperature is from 6,1 to 7,0 °C, relative humidity 94 to 99 %.
The bones of cave bear (Ursus spelaeus) were found in the Bear’s Passage (Medvedia chodba). The finding of the palpigrade Eukoenenia spelaea means one of the most northern occurrences of this arachnids in the world, which ranks the cave among the biospeleological localities of European importance. From among the tiny invertebrates, mostly the multipede Allorhiscosoma sphinx (endemite of the middle Slovakian caves) and amphipods Synurella intermedia a Niphargus tatrensis are important.