Located in the southwestern province of Khuzestan, the ancient fortress city of Shushtar is a magnificent reminder of Sassanid era. Having different names in various historical periods namely Adamdun in the Elamite times and Surkutir in the Achaemenid period, the city’s current name is related to Susa, the other ancient city nearby.
As an island city on Karoun River and the summer capital of Sassanid rulers, the city owes much of its popularity to the unique historical irrigation system or water mills on the first Dam Bridge in Iran called Kaisar (Qeysar) Dam, offering optimal use of water in ancient periods.
Originally built by the Achaemenid King Darius the Great in the 5th century BCE but renovated and expanded by Sassanid engineers, Shushtar historical hydraulic system is a spectacular complex of rivers, dams, waterfalls and canals. One out of two main diversion waterways of the system is still being used, providing water to Shushtar mills.
Following the battle with Roman Emperor Valerian, Sassanid ruler Shapour I ordered captured Roman soldiers to construct Kaisar Dam on the Gargar Canal with branches off the Karoun river, making the water level rise to enter three manmade canals carved on the rocky environs and flow into many branches in various directions to end up feeding the adjacent watermills before pouring down into the water pools on the other side.
Also, a tower was built near watermills as the main headquarter to supervise the smooth running of the hydraulic system which was used up to the Qajar era. Currently, the system has been reconstructed by several dams based on modern technology and like the past it is aimed at storing water for irrigation and electricity production.
Regarding the significance of Shushtar, it should be mentioned that the noted French archaeologist Madam Jane Dieulafoy in his travelogue described the complex as the biggest industrial complex before the industrial revolution.
The whole site comprising Salasel Castle, dams, bridges, basins, mills, waterfalls, the operation center of the hydraulic system, and the tower has been registered on UNESCO’s World Heritage List as “a masterpiece of creative genius” and has been attracting a large number of domestic and foreign tourists to enjoy both the amazing landscape and the rare historical water engineering technology.