On the north side the Aula opened on to a monumental portico with Carystian marble columns, overlooking the palace forecourt and from where the emperor received the salutatio, the traditional morning ceremony.

The poet Statius, a contemporary of Domitian, described the splendour of the Flavian Palace, particularly the Aula Regia,[2] in Silvae, IV, 2: Awesome and vast is the edifice, distinguished not by a hundred columns but by as many as could shoulder the gods and the sky if Atlas were let off.

The Thunderer’s palace next door gapes at it and the gods rejoice that you are lodged in a like abode […]: so great extends the structure and the sweep of the far-flung hall, more expansive than that of an open plain, embracing much enclosed sky and lesser only than its master.

Two huge statues of metallic-green Bekhen stone (an especially prized sandstone from Egypt)[5] representing Hercules and Bacchus were found in situ during excavations in the 18th century; they became part of the Farnese Collection and are housed in the Archaeological Museum in Parma.

Misnamed by 18th century excavators as a shrine for the Lares (household gods),[9] it was more likely a room for the Praetorian Guard since it is immediately east of the Clivus Palatinus, where visitors to the palace would have arrived.

Behind the "Lararium" was once a staircase providing access to the Domus Augustana below which parts of the earlier House of the Griffins have been excavated and from which exquisite decorations have been removed to the Palatine Museum.

The main entrance to the west led first into the Aula Ottagonale with elaborate triclinia on each side, and then into a huge peristyle garden almost completely occupied by a lake-like pool in the centre of which was a unique octagonal island with a labyrinthine pattern of channels and with fountains, all veneered in precious marble.