Predjama Castle (built within a cave) – Slovenia

Predjama Castle is a Renaissance castle woven within a cave mouth in southwestern Slovenia. It was built in the Gothic style and first mentioned in 1274. It is truly an architectural masterpiece. The structure was constructed under a natural rocky arch high in the stone wall to prevent easy access. The castle has changed hands many times throughout history. Probably the most infamous owner was knight Erazem, who controlled the land in the late 15th century.

Predjama Castle is located in the middle of a 123m high, overhanging, limestone cliff. It has numerous secret passage ways, including a natural shaft that leads out of a secret room. The shaft was used to supply the castle with food during a time of siege and also for smuggling and criminal activity. Over the years the structure has had numerous ghost sightings and reports of paranormal activity. In 2008, it was featured on an episode of Ghost Hunters International on the Sci Fi Channel. The castle was eventually confiscated by the state after World War II and today it is used as a museum showcasing the life of medieval lords.