Postojna Cave and Predjama Castle are world-class attractions. The most visited tourist cave in Europe is a place where the proteas or olm offspring are once again hatching. The cave railway has been operating at the cave for 140 years. The cave is connected to Predjama Castle, the largest cave castle in the world. A legendary tourist train takes you to the underground network of karst tunnels, galleries, and halls. Postojna Cave is the only karst cave with a cave railway. For 140 years it has been taking visitors to see stalactites and stalagmites and other features created by water. Predjama Castle is located in the vicinity of the Postojna Cave and is the largest cave castle in the world. For over 800 years it has been guarding a rock face, 123 metres high. Mysterious underground tunnels connect it with the cave directly beneath. The castle, which has also been a film location, offered refuge to its legendary owner Erazem Predjamski in the 15th century. This robber knight resisted a siege for over a year in his castle with its incredible appearance and location.