Fodor's Expert Review Museo delle Mura

Rome's first walls were erected in the 6th century BC, but the ancient city greatly expanded over the next few centuries, and when Rome was at its peak, it didn't need walls. In the 3rd century AD, however, Emperor Aurelian commissioned a 12-mile wall to protect the city. Although many considered this a sign of weakness, it was more than a century before those walls were first breached in a siege that would herald the end of the empire. The ancient walls eventually became the fortifications of the papal city, and remained in use for 16 centuries until the unification of Italy in 1870. Studding the Aurelian Walls were 18 main gates, the best preserved of which is the Porta di San Sebastiano at the entrance to the Via Appia Antica. This gate is also home to a small museum that allows you to walk a section of the ancient ramparts and take in some truly wonderful views. Note that the museum closes relatively early, at 2 pm.