The Archaeological Museum houses the oldest ruins of the city dating back to the 1st century BC, with Etruscan, Italic, Hellenic and Roman finds. It is located within the small deconsecrated church overlooking the Roman Theatre, in the cloister and in the cells of the Jesuit Convent.
Some of its antiquities are statues of pagan gods, sphinxes and figures of women, funerary inscriptions, bronze and marble sculptures, vases from different necropolises, glass objects and complex Theatre decorations. There are also parts of the Roman aqueduct built on Ponte Postumio, and precious mosaics of the second century coming from Roman houses. Some examples are famous representation of gladiators with their armour and the cult of Dionysus with the four panthers.
In the Sacred Inscriptions hall you can see on the floor the 18-metre-deep and 2-metre large cavity which was used to protect the theatre from infiltrations, by discharging water into the river.