Just outside the station, and extending into it (part is in the metro station) is a section of Rome’s earliest defenses, the Servian Wall. Built more than 23 centuries ago, it has much to tell ...

The finds mostly corroborated evidence unearthed at other sites. Most significant discovery: remnants of the Servian wall, built in 387 B.C., which gave new clues to the urban layout of early Rome.

From the Trojan Wall to Hadrian's Wall to the Great Wall of China to the Servian Wall, walls are pretty good at keeping people out as well as in.