About 200 million years ago, enormous quantities of shells, coral formations, fish skeletons, sand, slime and calcium carbonate, chemically precipitated through water evaporation, began to settle at the bottom of a sea which could correspond to the actual Tyrrhenian sea. This detritus, though varying in quantity and composition, kept accumulating, layer upon layer, for at least 170 million years, forming a mass thousands of metres thick. The great weight of such an accumulation, brought about the compression and the cementation of the various elements, slowly transforming them into limestone rock.
About 20 million years ago, strong thrusts (orogenic movements), linked to the movement of the earth's crust, caused the upheaval of this rocky body, the great pressure fracturing it enormously, causing it to emerge from the sea and to slowly form the mountains we see today.
The name (Wind Cave) derives from the violent air current which runs through the cave, due to the presence of two openings which are situated at different levels.
The lower opening (Tourist Entrance) is situated at 627m. above sea level, whilst the higher opening (which is inaccessible) is 800m. further up at over 1400m. above sea level. The internal temperature constantly maintains itself at 10,7 degrees centigrade.
We have therefore, an air current which in summer, being cooler than the external air, is heavier, therefore creating an "outgoing" wind at the lower entrance (incoming at the higher entrance). The situation in winter is reversed: the outside temperature is nearly always lower; the inside air, warmer and therefore lighter, rises creating an incoming wind at the lower entrance (outgoing at the higher entrance). The speed of the wind is directly proportional to the difference between the internal and external temperatures. During tours the armoured door blocks the air current almost completely.