The Band-e Kaisar ("Caesar's dam") was a Roman arch bridge, and the first in the country to combine it with a dam. When the Sassanian Shah Shapur I defeated the Roman emperor Valerian, he is said to have ordered the captive Roman soldiers to build a large bridge and dam stretching over 500 metres.
Lying deep in Persian territory, the structure which exhibits typical Roman building techniques became the most eastern Roman bridge and Roman dam. Its dual-purpose design exerted a profound influence on Iranian civil engineering and was instrumental in developing Sassanid water management techniques.
The approximately 500 m long overflow dam over the
Karun, Iran's most effluent river, was the core structure of the
Shushtar Historical Hydraulic System, a large irrigation complex from which
Shushtar derived its agricultural productivity, and which has been designated World Heritage Site by the UNESCO in 2009.
The arched superstructure carried across the important road between Pasargadae and the Sassanid capital Ctesiphon. Many times repaired in the Islamic
...see more period, the dam bridge fell out of use in the late 19th century, leading to the degeneration of the complex system of irrigation.
Reference: www.wikipeida.org