Located to the south end of the Domitian Street, it is the first structure in Ephesus known to be dedicated to an emperor. It was built on a high and wide terrace set by 50x100 meters in size, on vaulted foundations. The northern size of the terrace seems to be two-stories high, reached by stairs. The stairs are still visible today.
The temple, built in pro-style plan, had eight columns on the short side and thirteen columns on the long side, and four additional columns in front of the cella. At the northern side there was an u-shaped altar, which is now displayed in Izmir museum.
It was in the reign of Domitian that an emperor gave permission to built an Emperor Temple; that is the permission to be the 'neocoros' for the first time, which was a great honor for a city.
When the unpopular emperor was killed by his servant, public quickly took vengeance and erased his name from many inscriptions. However in order to not lose its neocoros status , the Ephesians re-dedicated the temple to Vespasian, the father of Domitian.