river, southern Turkey, rising in the Nurhak Mountains of the Eastern Taurus range, northeast of Elbistan. It flows southeast past Elbistan, where it is fed by the Harman Deresi and numerous other small streams. It then turns south, is joined by the Aksu on the outskirts of Kahramanmaraş, changes course toward the southwest, and empties into the Mediterranean Sea after a course of about 316 miles (509 km). The region through which the river flows was once part of the Byzantine Empire; its present name is the Turkish form of the Arabic Jayḥān, which was applied to both the river and the region.