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

A Nesting Doll of Churches.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

A sunken idol welcomes parishioners to Davy Jones' Locker.

Five candy-colored villages on the Italian Riviera.

Virgil's many-mouthed gateway to the underworld.

Pilgrimage site for star-crossed lovers.

Medieval town turned hippie commune, once home to the secret foreskin of Jesus Christ.

Go inside to really appreciate this 500-year-old technological masterpiece.

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

2300-year-old Roman road connecting the empire.

The oldest operating pharmacy in the world features 800-year-old recipes.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

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

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

The glowing blue Nymphaeum of Emperor Tiberius.

Rome's semi-secret peephole vista is also a former Crusader stronghold.

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

The middle finger of modernity.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

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

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.