The Koritnica, with a length slightly over 16 kilometers (9.9 mi), is a right tributary of the Soča River. It flows west through the Log Koritnica Valley south of Mount Mangart and then turns south near Log pod Mangartom, flowing past the Kluže Fortress and through the 70-meter (230 ft) deep and 200-meter (660 ft) long Kluže Canyon, also known as the Koritnica Canyon. It empties into the Soča southeast of Bovec.