Salasel Castle (Shushtar Castle) is located along Shatit River in the northwest of Shushtar. The Castle which dates back to the Achaemenian era (550-330 BCE), had defensive and political functions as well as the operation center of Shushtar Hydraulic System. The castle was also used as the governor’s residence and as a shelter during wars. Salasel castle is where Shaour I the Sassanid King, is said to have imprisoned the Roman emperor Valerian. It is also said that Persians held out for two years against the invading Arab army.
Shushtar Salasel Castle was a massive fortress containing several courtyards, bathrooms, large pools, barracks, stables, underground quarters, and gardens, round towers, armory, kitchen, and moat. The Salasel Castle was registered as one of Iran’s national heritage sites in 1976.