The Sava Dolinka is a headwater of the Sava River in northwestern Slovenia. The 45 kilometres (28 mi) long Sava Dolinka starts as Nadiža Creek in the Planica Valley under Mount Zadnja Ponca in the Julian Alps, at an elevation of 1222 m, close to the Italian border. The stream goes underground soon after its source and breaks out again after 5 km at an elevation of 842 m in Zelenci, near Kranjska Gora. The Sava Dolinka flows through Kranjska Gora, Gozd Martuljek, Jesenice, between Bled and Breg, and past the town of Lesce. The first in a series of hydroelectric power plants on the river, the Moste Hydro Power Plant (22.5 MW), is located near Žirovnica. It merges with the second major headwater of the Sava, the Sava Bohinjka, at Radovljica.