On 30 May 2016 at 10:48, Postojna Cave, one of the most stunning karst caves in the world, was the location of the hatching of the first baby human fish since this rare aquatic salamander began laying eggs in January. It was a historic event which could be observed for the first time in the 200-year public history of the cave. The miraculous birth, which was closely followed by the public all over the world, could inspire you to visit the karst underground and learn about its most famous dwellers – the human fish, also known as "baby dragons".

The first dragon

Every new life is a miracle. It is that much more special if the life in question is of a “little dragon.” The baby olm came into the world exactly four months after the parent laid its first egg in the aquarium. It evidently could not wait to come out, as it literally “shot out” in a single try. In order to become familiar with its home, it first swam around the aquarium before calming down at the bottom of the tank. Its arrival into the world was filmed by infra-red cameras, and the first footage of the hatching of an olm egg holds a priceless value for biologists. You will be able to see this when you visit the Postojna Cave.

This time, the cave miracle that usually occurs in the dark depths of subterranean water happened right in front of the eyes of visitors, in an aquarium that you can reach by taking an underground train. Because olms cannot be easily seen in nature, this is the only way for us to get a look at them up-close. For this reason, the emergence of the offspring was such a special and rare occurrence and was carefully followed all over the world.

One of the proteus females laid some eggs in 2013, but none of the offspring managed to hatch. This time, biologists were much more careful when taking care of the development of the eggs.

A mysterious mythological creature

Even though the olm has lived in caves for millions of years, very little is known about them. People first saw olms in the 17th century, when a river flushed them out of their natural habitat following heavy rainfall. People used to be convinced that a fearsome dragon lived in Postojna Cave, people were convinced that these unusual creatures were its offspring. This is why the human fish are also known as "baby dragons".

It is known today that the olm or the human fish is the only vertebrate which solely inhabits the underground and that it is the largest cave predator, although it grows to only 30 to 40 cm in length. This small animal is fully adapted to life in the dark, as its skin does not contain any protective pigmentation, and its light pink colour is due to the capillaries under its skin. The olm could advise us how to enjoy a long life, as it lives up to 100 years, and is very slow and inactive. Its “mythological” characteristics also stem from its “poor appetite,” as it can last without food for up to ten years, and it only reproduces every six or seven years. The olm is blind, as it does not have eyes, and in addition to its heightened sense of smell, it also uses electrical power and magnetic waves to detect its surroundings.

A sign of clean water

The most important aspect of the olm is certainly that it only lives in extremely clean water. If olms disappear from water, this may indicate pollution, so Slovenians are glad that “little dragons” have lived in its underworld for so long.

Not only is the water in Slovenia clean, but it also covers a significant part of its territory. Locals can enjoy no less than 1300 natural and artificial lakes, springs, waterfalls, rivers, and the sea. Having more than 27,000 kilometres of a rich and ramified river network and 54,000 kilometres of river banks and lake shores, Slovenia is one of the richest countries in the world when it comes to water.

One of the most beautiful caves in the world

Postojna Cave is considered one of the most beautiful and most biologically diverse karst caves in the world. Under the surface, the River Pivka has created a magical world of mysterious tunnels, underground halls, and galleries with stalactites and stalagmites, which have been attracting visitors for over 200 years. Come and see what has been inspiring locals and witness history in the making. 


Also visit museums that house the greatest treasures of Slovenia. Marvel at the special features of the landscape in protected nature areas. In the Karst, which lent its name to all karst phenomena throughout the world, you can also learn about the special features on the land surface, and not only those found in karst caves. All types of accommodation await you in the vicinity of major attractions.

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