Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

This equestrian statue of Constantine the Great has been the subject of criticism for centuries.

The once forbidden "secret cabinet" of erotic art from excavations of Pompeii and Herculaneum.

Locals pay their respects at a shrine to soccer player Diego Maradona—which claims to contain a real lock of his hair.

This 17th-century passageway is home to numerous bookshops, a witch legend, and the oldest pizzeria in the world.

The Neapolitan Cult of the Dead still cares for the skulls at this mini-Fontanelle.

Every day is like Christmas on this street where the traditional Neapolitan nativity scene comes to life.

Pompeii's less famous neighbor is still revealing her secrets.

This amazingly well-preserved villa just outside Pompeii boasts rare examples of ancient Roman paintings.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

Ancient snack bar of the Roman Empire re-opened.

The underground sanctuary of a mysterious ancient cult.

The yawning maw of this pagan visage is said to bite off the hands of liars.

The best preserved Paleochristian basilica in Rome hides a number of oddities and secrets.

Rome’s legendary peephole vista is also a former Crusader stronghold.

This picturesque Umbrian city has a subterranean side that has long remained hidden.

Nine caves filled with recently-discovered archaeological finds under the houses and the streets of the most ancient district of an old town.

Water and windows define this defensive Italian well.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

This ancient Roman aqueduct once funneled water to Diocletian's palace.

The big toe of this towering monument to a Croatian national hero is worn from years of superstitious rubbing.

A musical instrument played by the sea.

Now harmless, this looming post struck fear into the heart of medieval troublemakers.