Ctesiphon was an ancient city located on the eastern bank of Tigris. The archway is the last remaining structure and was once a part of the royal palace in Ctesiphon and is estimated to date between the 3rd and 6th centuries AD.

The arch is in remarkably good condition considering its age. The structure was captured by the Arabs during the conquest of Persia in 637AD and then used for a while as a mosque before being gradually abandoned.

The late afternoon sun shining through the arch, which is also the largest single-span vault of unreinforced brickwork in the world.