Postojna Caves – 27 Kilometres of Cave Wonder in Slovenia

Geography: The Karst and Its Underworld

Postojna lies in the karst region of western Slovenia, 50 kilometres southwest of Ljubljana and 100 kilometres north of Trieste. The very word "karst" – used worldwide today for a specific type of landscape – comes from this region: the Slovenian word "kras" (stony land) became the international technical term for limestone landscapes with underground cave systems, sinkholes and disappearing rivers.

The Pivka River flows above ground into a basin and then continues as an underground river – over millions of years it carved out the Postojna cave system: 27 kilometres of tunnels, galleries and halls, of which 5 kilometres are open to visitors.

History of Discovery

Parts of the Postojna cave system were known in the Middle Ages; local inhabitants used the entrance areas. The great discovery came in 1818, when the postal official Luka Čeč, preparing for an imperial visit, ventured deeper into the cave than anyone before him and discovered the vast interior. As early as 1823 – just five years after the discovery – guided tours were being offered. Emperor Franz I of Austria was the first prominent visitor in 1819.

Visitors have been coming for over 200 years; in total approximately 38 million people. During the Second World War, the German occupiers used the cave as a fuel depot – a fire in 1944 destroyed part of the equipment. The vast majority of the formations remained unharmed.

The Cave: Stalactites, the Narrow-Gauge Railway and the Olm

A visit to Postojna Cave begins with an unusual attraction: a 3.7-kilometre journey by narrow-gauge train through the illuminated tunnels – the only cave railway system in the world with regular public operation. This is followed by a walking tour through the "Concert Hall" (large enough for 10,000 people), the "Russian Bridge" (built by prisoners of war during the First World War) and the "Brilliant" – a 45-metre stalactite column regarded as the largest of its kind in Europe.

Postojna Cave is also home to the olm (Proteus anguinus) – a blind, white salamander that lives exclusively in the underground waters of the Dinaric Karst. The creature is considered a living fossil and can live for over 100 years. Specimens can be seen in the cave's vivarium.

Predjama Castle: The Middle Ages in a Rock Face

Nine kilometres northwest of Postojna stands Predjama Castle – one of the most extraordinary castle complexes in Europe. It was built literally into a cliff cave: the castle itself is only part of the complex; behind it lies a 574-metre-deep cave system that served as a secret passage. Erazem of Lueg, a 15th-century robber baron, held out through years of siege because he could be supplied through the secret passage – until he fell by treachery in 1484.