The karst cave at Postojna, one of the largest in the world, is among Slovenia’s most popular attractions and its stalagmite and stalactite formations are unequalled anywhere. It's a busy destination, and claims that it is visited by a third of all tourists coming to Slovenia – the amazing thing is how the large crowds at the entrance seem to get swallowed whole by the size of the caves.
The cave has been known – and visited – by residents of the area for centuries; you need only look at the graffiti dating back seven centuries in the Gallery of Old Signatures by the entrance. But people in the Middle Ages knew only the entrances; the inner parts were not explored until April 1818, just days before Habsburg Emperor Franz I (r 1792–1835) came to visit. The following year the Cave Commission accepted its first organised tour group, including Archduke Ferdinand, and Postojna’s future as a tourist destination was sealed. Since then more than 32 million people have visited the cave.
The town of Postojna lies in the Pivka Valley at the foot of Sovič Hill (677m). The Pivka River and the entrance to the cave are about 1.5km northwest of Titov trg in the town centre.
Postojna’s bus station is at Titova cesta 36, about 250m southwest of Titov trg. The train station is on Kolodvorska cesta about 600m southeast of the square.