Standing 9.00 meters above the Forum, Temple E occupied as prominent a place in the Roman city as the Temple of Apollo.
In its first phase, the temple had stone foundations, probably with a triple crepis measuring 44.00 x 23.50 meters, on which was constructed a limestone Doric temple with six columns across its facade. The temple enclosure was bounded by a wall to the west and by stoas on the north and south. It is dated to the early 1st century A.D., soon after the death of Augustus.
In the late 1st century A.D. the temple was radically altered. The new building was built in the Corinthian order on a podium 3.4 meters high and was surrounded by a colonnade of 6 columns across the short sides and 12 along the long sides. The temple had a pronaos with two columns in antis and a long, narrow cella. The temple was completely enclosed by stoas during this phase.
From Pausanias's description, his temple appears to have been dedicated to Octavia, the sister of Augustus.