What is "tresnjica"

Trešnjica is a river in western Serbia. The source of the river is situated on the Povlen mountain. After 23 km the Trešnjica joins the Drina near Ljubovija.

Right before the convergence with the Drina, the river has created a 500 ft deep limestone gorge with vertical cliffs. The area is a designated nature reserve of which the largest part is covered with forests and thickets of common hornbeam, turkey oak, black pine and juniper. Many birds of prey nest in the Trešnjica gorge, including golden eagle, common kestrel, goshawk, sparrow hawk and griffon vulture.