Band-e Kaisar

Band-e Kaisar means ‘Caesar’s Bridge’, and is also known as the ‘Bridge of Valerian’. It is located near Shushtar in Iran, then known as Susa.
It is a combined Roman Road, Bridge and arched Dam and is the easternmost Roman Monument, and has been a Unesco World Heritage Site since 2009 CE.

It was built by the captured Roman Legions after their disastrous defeat by the Persians under Shapur I at the Battle of Edessa in 260 CE.
Valerian was the only Roman Emperor to be captured and taken as a prisoner of war. The Legions then built the city of Bishapur where Valerian lived out his captivity.

The 1,600 ft (500 m) long Roman Dam consisted of approximately 40 arches over the River Karun. The Weir was an arched bridge carrying the road from Pasargadae to Ctesiphon. It was the first combined Bridge and Dam in Persia.
The construction took between 3 to 7 years to complete, and its Ruins are still standing.
As an overflow Dam, it was used to irrigate the surrounding area.
The Dam was subsequently copied by Persian engineers, influencing their techniques of hydraulic engineering.

In 266 CE, the captured Roman Legionaries built the nearby city of Bishapur, in the Province of Fars, where they, and Valerian, then lived.
The Legionaries built a Palace for Shapur I, with Roman Mosaics.
They also constructed the Temple of Anahita.

Shushtar Hydraulic System, Iran