Karun has the highest discharge among the rivers in Iran, while it is the longest river in the Country. The length of the River is 950^km and the area of its catchment is 60.000^km . Karun is the only River in Iran which is navigable by boat. The source of the Karun is called Abkaj, located on Zardkuh-e Bakhtyari Mountains. The River originates from the Zagros Mountain Range. After winging through mountainous areas and flowing into the Khuzestan Plain, it reaches an area named Gotvand. The Karun is divided into two branches in the north of Shushtar, joining each other again on the south of Shushtar. The main branch of the Karun is the Dez River, which is joins the Karun on the north of Ahvaz. The Karun joins the Arvand River on the Iran–Iraq boarder, and eventually flows into the Persian Gulf.