Shushtar Historical Hydraulic System
Shushtar’s historic hydraulic system, a UNESCO-listed tangible cultural heritage, is an interconnected set of bridges, spillways, dams, mills, waterfalls, canals, and tunnels. It dates back to the Achaemenid period, with most of its construction during the Sassanid era. The system optimally uses water via ancient purification techniques and is still partially functional today. It was called the largest industrial complex before the Industrial Revolution by French archaeologist Jean DeLafoy. Karun, the only navigable river in Iran, splits into two branches named Gregar and Shatit before entering Shushtar. Gregar is an artificial channel attributed to Ardeshir I, the founder of the Sassanid Empire. The Gregar Dam was built to raise its water level. Three tunnels transfer the water supplied by the Gargar Dam to the complex. The incoming water is divided through several channels, turns the mill wheels, and then cascades into a pond. The complex is a magnificent example of ancient civil engineering, with granite and lime plaster as the primary building materials.