Baḥr al-ʿArab, intermittent river of southwestern Sudan, rising northeast of the Tondou (Bongo) Massif, near the border with the Central African Republic. The river flows 500 miles (800 km) east-southeast to join the Baḥr al-Ghazāl, a tributary of the Nile River, at Ghābat al-ʿArab in South Sudan. It is not navigable and is subject to floods in summer.