Viale di Porta Ardeatina 13-17
+39 06 0608 (Tourist Information)
The 19 kilometer (62,336 feet) long wall at the outskirts of the seven hills of Rome
is an architectural wonder. It marks the boundary of the old city and is one of the most ambitious projects in the history of Rome. Built in 271 CE it was a security against the barbarian attacks of that period, constructed by Emperors Aurelius and Probus. It has around 19 gates at various locations for access. It took five years to build the wall made of concrete. Remarkably, the wall is relatively well-preserved today, and can be admired best near the Porta Ostiense and the Villa Borghese.