Predjama Castle is built directly into the mouth of a cave, halfway up a 123-metre vertical cliff in the Slovenian karst. The current Renaissance structure dates to 1570, but a fortress has stood here since at least 1274 — making the site continuously inhabited for over 750 years. The cave behind the castle extends 14 km into the hillside, giving the medieval occupants a hidden supply route that no besieger could easily block.
The castle's most famous resident was Erazem Lueger, a 15th-century knight outlawed for killing a relative of the Habsburg emperor. He retreated to Predjama in 1483 and held out against a year-long Imperial siege — eating fresh fruit and game brought in through the secret cave passage, taunting his besiegers from the battlements. He was finally killed in 1484 not in combat but on the toilet, betrayed by a servant who signalled the siege engineers when he visited the castle's most isolated outer chamber. The cannonball that killed him is still on display.
A self-guided audio tour (90 minutes, included with entry) covers four levels of fortified rooms — kitchen, chapel, knight's hall, dungeons, and the upper passages where you look down into the cave throat behind the castle. The cave itself is open as a separate tour from May to September. Predjama is 9 km from Postojna Cave and is almost always visited in combination — buy the combo ticket (€43.50) at either site. From Ljubljana it's a 55-minute drive; from the cave itself, 15 minutes.
