Things to see
The Emperor Maxentius reinforced the walls in 354, doubling the height of some sections of the wall and apparently adding a ditch which was never completed. Many other changes appeared under the reign of Honorius (393-423), namely the improvement of both the wall and its towers. In 403, the Tomb of Hadrian was included in the wall and became a military building. Despite these many improvements, the Visigoths led by Alaric entered the city in 410.
The Porta San Paolo (“Saint Paul Gate”) is located on the ancient Via Ostensis. This road connected Rome to Ostia Antica. Originally, Porta San Paolo was named Porta Ostiensis however it was renamed after the basilica located near the gate. Its defensive system has survived time practically intact and has been preserved just as it was first installed.
Unfortunately, only 13 kilometers of the Aurelian Walls remain today; they are also obsolete as the city has long since expanded outside the protection of these walls.