To witness of the Roman era, in Susa remain numerous and important monuments: in the first place the Augustus Arch, built in 8 BC to enshrine the pact of alliance stipulated between Cozio, local sovereign, and the empire of Rome; the rocks coppellate Celtic, witness of history segusina oldest; the aqueduct of Graziano (IV sec. d.C.); the Castrum (IV century d.C.), the arena Steve (II century d.C.), the Porta Savoia (III – IV sec. d.C.), which was resting in The XII century, the Cathedral of San Giusto; the traces of the ancient walls still preserved along the via dei Fossali (Current Soviet Union). The restoration works of the central Piazza Savoia have also brought to light some important structures, which archaeologists identify as the remains of urban temple, placed at the center of the hole.