The Vrelo cave near Fužine in the Gorski Kotar mountain region sits 3 kilometres from the centre of Fužine town via the road along lake Bajer, estimated to be 3.5 to 4 million years old. The total length of all cave canals is 300 metres. Around 250 metres is open to visitors. At the end of the cave is a water source, while in rainy seasons the cave is full of water, which along with numerous stalactites makes it very attractive. The entire length of the cave has illumination, and the straight path without steps makes it available for visitors in wheelchairs. The year-round temperature in the cave is 8 degrees Celsius.