This circular monument stands at the centre of the Forum square and is traditionally interpreted as the shrine of the Lares Augusti (the gods who protected the emperor).

The identification is based on the attribution to this monument of an inscription, not found in situ, commemorating the construction of a temple dedicated to this cult in around the mid-1^st century AD.

Inscription probably belonging to the architrave of the shrine with a dedication to the Lares Augusti

Another theory identifies the monument as a nymphaeum, in part based on the presence of an internal coating of hydraulic lime.

Inscription probably belonging to the marble revetment of the shrine