Postojna Cave: The Underground World of Slovenia
1818 · place
In April 1818 a local lamplighter named Luka Cec was preparing the known part of a cave near Postojna for a visit by the Austrian emperor. Climbing across a rock face, he found himself looking into a passage that no one had entered. Beyond it lay chamber after chamber of white and ochre formations, a river running underground and galleries stretching for kilometres. Postojna Cave, which people had visited for centuries and had signed their names in since the thirteenth century, turned out to be far larger than anyone had thought.
The cave lies in the Slovenian karst, the limestone landscape that gave the word karst to geology worldwide, where rain sinks through cracks and dissolves the rock into caves, sinkholes and vanishing rivers. Today about twenty four kilometres of passages are mapped, and visitors travel through them on an underground railway that has been running since 1872, one of the first of its kind anywhere.
The cave has a famous resident. The olm is a pale, blind amphibian up to thirty centimetres long that lives its whole life in the water of these caves, can survive for years without food and may live for a century. Local people once believed that the animals washed out by floods were the young of dragons, and the creature is still called the human fish in Slovene because of the colour of its skin. In 2016 a female laid eggs in the display aquarium and the hatching was followed around the world.
Postojna has received more than forty one million visitors, which makes it the most visited show cave in Europe. For Slovenia it is both a landmark and a laboratory, the place where the study of caves began as a science, and where a small country keeps one of the best documented pieces of underground Europe.