Shushtar (shōshtärˈ) [key], town (1991 pop. 70,294), Khuzestan prov., SW Iran, on the Karun River. It has irrigated agriculture and has long been known for its brocaded textiles, metalwork, and engineering projects. It was at Shushtar that Shapur I, after his great victory (A.D. 260) over Valerian at Édhessa, set his captives to work building vast hydraulic works, including a large dam across the Karun River. Later, under the Mongols (13th–14th cent.), Shushtar was a beautiful and prosperous town. It was captured by Timur in 1393 and by Shah Ismail in 1508. After the 18th cent. it declined in importance. A serious outbreak of plague occurred there in 1876.