Domus Augustana set in gardens was a private imperial residence, that of the august one. Its concave façade opens out towards the Circus Maximus. The rooms were laid out around two peristyles, in the centre of which was a pool. One of the rooms, which opened onto the upper peristyle, was the Loggia Mattei, built by the Mattei family in the 16C and adorned with elegant frescoes, some of which date from 1520, while others come from the Isis Hall of the Domus Flavia.