Postojna cave

Postojna Cave is the best-known cave in the world. It is also the greatest tourist attraction in Slovenia and one of the world's largest Karst monuments.
What makes Postojna cave a must-see attraction of Slovenia? Starting with a unique and adventurous ride with a special train, it is one of the most diverse cave systems in the world, with 21 km of passages, galleries and magnificent halls, which offer an unparalleled experience of the underground world and a large diversity of underground animals – including the world famous human fish (proteus anguinus). The temperature in Postojna cave is a constant 9º C / 48 Fahrenheit, so you need to bring some warm clothes and comfortable shoes.