Postojna cave system is the largest cave system in Slovenia and one of the largest ones in the world. Underground world of Postojna was formed by the river Pivka over millions of years. During the ride by electric train and later on during the walk through different halls of the cave you will have a chance to admire spectacular stalagtite and stalagmite formations, expansive cave areas and also a special salamander-like creature, an amphibian called 'human fish' or Proteous anguinuius.

Some 8 km away you will visit one of the most magnificent buildings in Slovenia, the Predjama Castle, dating back to the middle ages, hanging in the mid of over 100 m high cliffy rock. The most famous owner was Erazem Predjamski, a hero of many local legends.