postonjska jama

A Must Go place if you are in Slovenia. This karstic cave system is the second biggest cave system in the world (20 km) which is actually open for the public. When I was there two years ago we could only go on a guided tour as they don't want people wandering around and destroying the cave. The guides are very friendly and speak several languages. A good advise: Take some warm clothes with you even when its sunny outside.