The source is at an altitude of 1200 m and flows along a former glacier valley between the mountain chains of Javoršček and Polovnik, flowing out to the Soča as the left tributary.

The stream has a very large and uneven drop, and in the middle part it formed troughs where the water falls in the form of a waterfall.

A large part of the river basin spreads on dark grey-brown flysch from the Cretaceous period.