The Vrelo cave in Fužine was discovered by chance in the 1950s during the construction of the Bajer reservoir. Its age is estimated at 3.5 – 4 million years. Although it is only 300 meters long, it is extremely beautiful and rich in cave decorations. The special value of the cave is given by the water – at only fifty meters there is a beautiful mountain spring, lake and abyss that make it especially attractive. The clear and cold mountain stream is from the Ličanka river basin and floods the cave in extremely rainy periods.