Wikipedia
Naysān (also known as Jabal Khayabar and Naisān) is a tell and an archaeological site in southern Iraq.
The tell has not been excavated due to ongoing conflict and instability in the area, however, a preliminary survey was conducted in 1965. That survey identified a series of impressive bastion walls of baked brick and significant pottery shards on the surface. The shards that could be identified belonged to the Sasanian or early Islamic periods The city was a trapezoidal shape approximately .
The site has been identified as the ruins of Charax Spasinu. This claim is based on the scale of the ruins, the fact that the local name for the ruins is Naysān which is probably a corruption of the Parthian name Maysān, and the location of the ruins at the confluence of the Tigris and Karkheh Rivers as stated of Charax Spasinu, by Pliny the Elder.