KARUN RIVER (Rud-e Kārun), the largest river and the only navigable waterway in Iran. It flows out of the central Zagros range, traverses the Khuzestan plain, and joins the Shatt al-Arab before the latter discharges into the Persian Gulf. This entry will be divided into the following three sections:

i. Geography and hydrology

ii. Historical geography

iii. The opening of the Karun