Postojna, the town that sits on top of an underground world

A crossroads town with a world beneath it

Postojna has 10,043 inhabitants and heads a municipality of 17,192 people and almost 270 km² in Notranjska. It sits on the railway linking Ljubljana with Rijeka and Trieste and beside the A1 motorway, which explains its historic role as a place people passed through. The tourist office stresses that here history begins not in books but in nature, and beneath the town lies one of Europe’s largest cave systems.

Local legends grow out of that landscape, such as the shepherd boy Jacob, who beat the cave dragon with wit rather than strength; the knight Erasmus of Predjama; and the White Snake of Mount Nanos. Jacob’s tale has even inspired a cake, with raspberries, pears and walnuts over a cottage cheese cream.

The two visits that bring everyone here

Postojna Cave has 19.5 km of passages and an underground train running since 1872, which the Slovenian Tourist Board ranks as Europe’s most visited show cave. It is 500 m from the town’s bus station. About 9 km from the cave entrance stands Predjama Castle, set into a 123 m cliff for over eight centuries.

What to see in Postojna besides the cave

First, the Notranjska Museum. Its Karst Museum exhibition explains how the karst landscape formed and which animals lived here, Neanderthals included, and it holds the Predjama Castle treasure, hidden for centuries in the cellar and found during the 1990 to 1993 restoration. It has activities for children, it is fully accessible and parking is free. It is also the perfect plan for a rainy day.

Then the Majlont quarter, the oldest part of town, with narrow streets and historic houses, and the 18th-century parish church in the centre. On Sovič hill stand the ruins of Postojna Castle, Adelsberg in German, with a view over the town. The tourist office also mentions a historic barber’s shop turned museum and Neotropica, a centre with tropical rainforests, coral reefs and tropical wildlife.

Once your dates are set, check which hotels are still free in Postojna before prices climb.

The surroundings

On the edge of Planinsko polje lies Planina Cave, where the Pivka and Rak rivers meet underground to form the Unica, one of Europe’s largest underground river confluences according to the tourist office. The standard tour covers 500 m with a guide in about an hour, but the cave is closed for bridge works, with reopening expected on 1 April 2027. Nearby are the ruins of the Baroque Haasberg castle and Ravbar Tower.

In the village of Predjama, next to the castle, the Gothic Church of Our Lady of Sorrows dates from the 15th century, and above the village of Studeno, the Church of St Lawrence is a well-known viewpoint. For families there is also a forest adventure park, a short walk from the cave, with around 90 climbing elements for ages four and up. Near Belsko, the Toplar hayrack, a fine example of rural Slovenian architecture, houses an ethnographic collection of more than 200 objects. And for real caving, the guided «In the Footsteps of Luka Čeč» tours lead through Postojna, Black and Pivka caves, away from the standard routes.

Getting there

By car, take the A1, exit 41. By train, use the line from Ljubljana towards Rijeka and Trieste; the station is about ten minutes’ walk from the centre. By bus, Ljubljana station listed 31 departures to Postojna on Monday 19 October 2026, taking 47 minutes to 1h12; details are in Ljubljana to Postojna. The whole region is covered in the guide to Notranjska.

Once your dates are set, check which hotels are still free in Postojna before prices climb.

A night in Postojna

Postojna is not a pretty town in the way Piran or Ljubljana are, and it does not need to be. It is the most convenient base for the cave and Predjama, and with the museum and Majlont you have a quiet afternoon’s worth. Staying here lets you catch the first cave tour of the day and forget about the last bus. If you are driving from Ljubljana, Logatec is on the way, with the Planinsko polje and Vranja jama cave.