The Slunjčica River rises to the surface 6.5 km south of Slunj. In the Rastoke district, the Slunjčica flows into the Korana, which flows from the Plitvice Lakes. At the confluence of the Slunjčica and the Korana, the river created a travertine barrier 500 m wide and 200 m long. Due to its relatively short surface course, the Slunjčica River always has a lower temperature than the nearby Korana. In summer, the Korana's maximum temperature is approximately 28°C. If the air cools below the water temperature, Rastoke is enveloped in a veil of fog, and the surrounding trees are covered with dew.