The temple was built by Vespasian in 74 A.D., as the partly restored dedicatory inscription on the pediment shows.

The capitolium site had a terrace on three sides with the temple in the middle and two lateral rows of arcades stretching down towards the Forum. The flight of marble steps, which has been restored and made up with bricks, led up to the podium of the raised pronaos, which is characterised by a hexastyle central porch with Corinthian columns about 11 metres high, which were restored during the nineteenth century reconstruction works. The temple has three aulae separated by cavity walls.

Large architraved doorways open into the cellae. The votive chapels have podiums in the centre. The marble-slab paving of the floors should not be overlooked; it is well preserved in the centre cella and the one on the left.The walls were probably faced with marble and decorated with engaged columns in Corinthian style, like those of the porch.

The temple bordered the north side of the Forum and was connected to the decumanus by a central flight of steps ending between two sections of marble-faced wall with blind arches. Traces of houses, burial places and productive plants of Longobard period can still be seen in the nearby archaeological area, superimposed or included among the remains of Roman worship buildings.

For this reason the archaelogical area is included in the UNESCO World Heritage List together with the complex of San Salvatore-Santa Giulia. The Forum , the civic and religious heart of Roman Brixia, acquired its final layout in the Flavian period (69 - 96 A.D.); it was rectangular measuring 139 x 40 metres, with its south side bordering on the Curia and its north side on the decumanus massimus.

The east, west and south sides were enclosed by arcades with a double order of richly decorated columns, under which there were a great many shops. The Basilica was on the south side of the forum- the remains of the front of this building with tall, grooved, Corinthian pilaster strips with windows and doorways in between can be seen incorporated in the house at no. 3 Piazza Labus, now the seat of the Soprintendenza per i Beni Archeologici della Lombardia.

The remains of the Basilica and of the Augustean Age Forum can still be seen in a small archaeological area on the ground floor.  A monolithic marble pillar 6.5 metres high with a Corinthian capital to the east of the square at 4.5 metres can be seen below the present street level. It was restored and the missing parts replaced with brick in the 1930s.