This was where Diocletian resided after his retirement. It currently holds his tomb. It was later converted into a Christian church, something the Lares and lemures who haunt the palace are unhappy about.
To retrieve Diocletian's scepter, Jason Grace and Nico di Angelo visited Diocletian's Palace. There, Jason left a note for Reyna Avila Ramírez-Arellano to let her know they would be in Epirus, Greece. They were intercepted by Zephyros, god of the West Wind, who led them to his master Cupid, the current possessor of the sceptor.
- Water for the palace came from the Jadro River in Dalmatia.
- The palace was built on the ground where Cupid and Pysche's palace once stood.