Via Garibaldi was the Decimus Maximus, the main street of the Roman city of Augusta Taurinorum. Near the cathedral, you'll see the imposing first-century gate, Porta Palatina, the only remaining of the four entrances to the Roman city.
One of the best preserved Roman gates in the world, Porta Palatina's three-story wall is constructed of brick and connects a pair of polygonal brick towers.
According to legend, Charlemagne camped below the gate in 773. Beside the cathedral are the remains of a Roman theater, also from the first century AD. Only part of it is visible, the rest of it having been covered over by the royal palace buildings.
