1 Best Sight in Piedmont and Valle d'Aosta, Italy

The 72-foot-high ruin of the facade of the Teatro Romano guards the remains of the 1st-century-BC amphitheater, which once held 20,000 spectators. Only a bit of the outside wall and seven of the amphitheater's original 60 arches remain. The latter, once incorporated into medieval buildings, are being brought to light by ongoing archaeological excavations.