Shushtar Historical Hydraulic System is an interconnected set of bridges, gangways, mills, waterfalls, canals and massive guiding tunnels that work together. The initial infrastructure was built during the Achaemenid and the Sassanian era for making more use of water.
Shushtar is an ancient fortress city, approximately 92 kilometres (57 mi) away from Ahvaz, the centre of the province. Much of its past agricultural productivity derives from the irrigation system which centered on the Band-e Kaisar, the first dam bridge in Iran.
The complete system was likely in place by the 3rd century CE, having incorporated the work and knowhow of various civilizations including the Mesopotamians and the Romans. Through the system of tunnels and pools, water is diverted to the city of Shushtar, powering several mills.