In draft Chapter 5 of Games of Rome, Gaius and Publius attend an audience with Emperor Trajan in one of the most grand and relatively well known spaces of ancient Rome. The imperial audience hall, often referred to as the Aula Regia, was part of the public rooms in the enormous palace built atop the Palatine Hill. The hall was reported to have had walls covered with thin slabs of highly-polished marble (essentially a mirror-like veneer designed to enhance light and security) and fabulous columns constructed of imported Phrygian marble.
Originally built by the architect, Rabirius, for the damned emperor, Domitian, the palace continued to be used as the official residence by most Roman emperors long after Domitian’s assassination in AD 96. In a huge apse at the far end of the vaulted room, the emperor would had sat atop his throne to receive visitors and emissaries, presenting himself in the guise of Jupiter, the chief god of the Roman pantheon.
Plan of the imperial palace on the Palatine Hill, Rome
The remains of the Aula Regia today.