In 224 CE, a Persian nobleman named Pâpak, son of Sasan, dethroned the lawful ruler in Persia, Artabazus V. As capital the new ruler chose Istakhr, not far from ancient Persepolis, the capital of the Achaemenids, with whom the new, Sasanian dynasty, identified itself. The Achaemenid royal tombs of Naqš-i Rustam are not far from Istakhr too.
The city was left after the fall of the Sasanian empire (the people went to Shiraz), and today, Istakhr is nothing but a plain full of sherds, and a few ruins, like this building, which is probably a gate. The site was older and antedates the Achaemenid age. The Sasanian town measures 1,400 x 650 meters and was surrounded by a ditch