Elagabalium

The Elagabalium was a temple built by the Roman emperor Elagabalus, located on the north-east corner of the Palatine Hill. During Elagabalus' reign from 218 until 222, the Elagabalium was the center of a controversial religious cult, dedicated to Elagabalus, of which the emperor himself was the high priest.

Archaeological site data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).