Predjama Castle

Predjama Castle is a Renaissance fortress built directly into the mouth of a large cave in a sheer 123-metre cliff in the Karst region of southwest Slovenia. The castle has occupied this dramatic position since the twelfth century and is considered the world's largest cave castle. Its position made it near-impregnable in the medieval period, and a system of tunnels through the rock allowed its defenders to resupply through the cave system behind it.