The center of the Salassi people in proto-history, they were slaughtered and enslaved by the Romans in 25 BC, a victory memorialized by a triumphal arch still standing outside the city wells. By 11 BC, the military settlement the Romans had established had developed into the capital of the Empire’s Grey Alps province thanks to its strategic position at the confluence of two rivers and two mountain passes. Today, the streets of Aosta’s old town still follow the Roman city planning, and the Roman ruins have been incorporated into the city. The walls and two gates are still preserved, and if you keep your eyes open, you’ll see buildings that are built on Roman foundations. The facade of the Roman theatre still stands today, and the Forum is annexed to the 11th century cathedral, which still bears an Ottonian fresco on the ceiling.