The subterranean world
Despite its small size, Slovenia is quite varied in terms of landscape. In the northeast it extends into the Pannonian lowlands, in the northwest it rises into the mountains of the Kamnik Alps, the Karavanke range and the Julian Alps, while its southwestern tip is bathed by the Adriatic Sea. Between the Alps and the sea, in the so-called Dinaric direction, runs the broad belt of the Slovenian Karst, which is part of the great Dinaric mountain range. This is a mainly limestone area notable for special karstic phenomena, both in the topography and underground.
This unique landscape is known as a karst. It was in the Slovenian Karst, in the 19th century, that scientific research into topographical features and underground formations began. The area between Vrhnika and Trieste, with Postojna in the middle, became the "classic karst" and the name "karst" (Slovene kras, German, Karst, Italian carso), used to designate special limestone formations, became a part of world geographical terminology.
When exploring the subterranean world, we often encounter great surprises. It is difficult for us to imagine how and when nature created the strange phenomena that a visit reveals, while the various speleothems (cave formations such as stalactites and stalagmites) that imitate nature are sometimes truly breathtaking. The karst underworld contains a variety of karst phenomena such as caves, underground rivers and wonderful stone sculptures. It is also home to numerous forms of life, and in fact the largest number of cave-dwelling species have been discovered in Postojna Cave itself. The largest and most famous cave animal is of course the "human fish".