The springs of Proboynitsa River are located in an old beech forest south of Kaluga Doll Peak. The crystal clear mountain water springs from the heart of the mountain, and descends rapidly down the deep valley. Folk beliefs impart miraculous and healing properties to the water that springs beneath the roots of the old beech tree.
As a result of the construction of the former Balkan Uranium mine, also known as the Proboynitsa mine, the lower reaches of the river are in poor condition. Today from this mine only the huge ballast mounds are being used. The construction is never finished and nearly 600m of underground galleries and shafts remain unused. In 2015, the construction of a small hydroelectric power station began near Proboynitsa.