The largest show cave in the continent, with a 3,200-metre-long (2-mile-long) track to whirr you around its caves and chasms, the Postojna Cave is genuinely otherworldly. Cathedral-size stalactites dangle from the ceiling of this 2-million-year-old cave complex, and its gigantic naturally formed caverns are so vast and acoustically sound that orchestras have been known to perform in them. It even has a post office – the world’s only underground postal service, buried 100 metres (328 feet) beneath the ground.
Formed by the crashing of the Pitka River into the rocky Slovenian settlement of Postojna, the caves have been explored by visitors since the 13th century, if carbon-dated graffiti marks are anything to go by. But the true appreciation of the caves came in the 18th and 19th centuries, when the Austro-Hungarian Empire, which controlled what we would now call modern-day Slovenia, saw their potential as a major tourist attraction. A local man, by the name of Luka Čeč, discovered far more to the caves as they were being cleaned in preparation for a visit from the archduke – as such, when the imperial crown provided the caves with the tracks and structure to be a natural exhibit, Čeč was made the first official cave tour guide.
Nowadays, the Postojna Cave remains one of Slovenia’s most beloved natural attractions, drawing hundreds of thousands of visitors every year to marvel at this phenomenal structure. Tied in with the enormous Predjama Castle, which serves as the cave’s entrance, a visit to Postojna is a must, being only 50 kilometres (31 miles) away from the increasingly popular capital city of Ljubljana. If you’ve ever wondered about the worlds that lie beneath your feet, then the Postojna Cave will show you all you’ve wanted to see, and so much more.