By hello
This 3rd-century Sasanian dam-bridge, also called the Bridge of Valerian or Shadorvan, combined a weir with a road bridge and strongly influenced later Iranian hydraulic engineering. Tradition connects it to Roman emperor Valerian, whose captured soldiers were said to have supplied the labor and engineering expertise after the Battle of Edessa. The bridge superstructure collapsed in 1885, but the remains survive as part of the UNESCO-listed Shushtar Historical Hydraulic System.