Persepolis, The centre of the great Persian Empire

Of these nine, the first three were built by Darius I (who also began the treasury building) and the rest completed by his successors, notably his son Xerxes I (r. 486-465 BCE) and grandson Artaxerxes I (r. 465-424 BCE). There were also residential buildings, a marketplace, and structures which archaeologists have yet to positively identify, at least one of which is most likely the palace of Artaxerxes I.