Interestingly, despite the most freezing temperatures and harsh and cold winters in the Alpine area of northwestern Slovenia, Lake Zelenci never freezes. It has a constant temperature throughout the year of 6°C. If you look carefully into the lake you will notice tiny bubbling ‘volcanoes’. These are a unique natural phenomenon in Slovenia. The lake is part of the Zelenci Nature Reserve, a wetland area in the far northwestern corner of Slovenia, near the village of Kranjska Gora. It is surrounded by several peaks of the Julian Alps. A visit to this area will easily make you see why it has been protected as a Nature Reserve since 1992. The area is approximately 15 hectares in total. It is possible to walk around the reserve in about 30 minutes.

Aerial view of the Zelenci Nature Reserve. (photo: Nikola Petkovic, Nixigraphy)

Surrounded by the vast peaks of the Julian Alps, Zelenci is famous for its small boardwalk and observation tower with views over the crystal clear green spring waters of the wetlands, and the limestone peaks of the Ponce mountain range. (photo: Jerneja Bergoc)

Lake Zelenci never freezes, no matter how cold it gets during brutal winters in northwestern Slovenia. (photo: Jerneja Bergoc)