See Inside the World’s Largest Cave Castle

Slovenia’s Predjama Castle sits halfway up a 400-foot cliff 
Predjama Castle
Predjama Castle is open for tours year-round.   Photo: VW Pics/Getty Images

Despite the majestic connotations of kings and queens dancing in remarkable ballrooms and dining in heavenly chambers, castles haven’t always been enchanting, and sometimes not even comfortable. As architectural historian Meredith Cohen shared in a recent YouTube video for AD, most medieval castles were defensive structures, designed to keep enemies out and those inside safe. And there’s no better place to see this than at Predjama Castle in Slovenia, the largest cave castle in the world, according to Guinness World Records

The castle’s facade was designed in the Renaissance style. 

Photo: JURE MAKOVEC/Getty Images

Sitting halfway up a 400-foot cliff and built into the mouth of a cave, this structure dates back over 800 years. Inside, rough stone walls line passageways and rooms, reminding visitors that they are just as much in a castle as they are in the body of, essentially, a huge rock. While there are some rooms with hardwood floors and stucco-like walls, interiors have been described as damp, cold, and “almost unlivable” by those who have visited.

Inside the castle, glossy wood steps contrast the mossy rock walls. 

Photo: Mondadori Portfolio/Getty Images

But the real showstopper isn’t the king’s chambers or the armory, but the connected cave and series of underground tunnels buried deep into the cliffside. Though the structure has roots as far back as the 13th century, the most famous tale featuring the impenetrable edifice begins a couple hundred years later during the 15th century. According to the legend, the castle became the hideaway for Erazem Lueger (also known as Erasmus), the son of Nikolaj Lueger, the imperial governor of Trieste.

“Adventure tours” allow guests to visit the cave beneath Predjama. 

Photo: Mondadori Portfolio/Getty Images

After carrying out a vengeful murder, Erazem, who was a known robber baron, enraged the House of Habsburg and quickly found himself in a battle with the Roman Empire. He found safety in the family castle, using the underground tunnels and cave to retrieve food and water without the opposing army noticing. The castle did its job, keeping Erazem safe for months on end. However, the legend states that he was sold out by a servant who lit a torch while Erazem was using the nearby outhouse, leading the Romans to shoot a cannon that killed the knight. 

These days, the cave is now home to a bat colony—not royal kinsmen—but if you’re willing to work around the winged mammals’ hibernation schedule, you can still visit it during the summer, from June through August. The castle, on the other hand, is open to tourists year-round.