This medieval Italian town is a sheer (and beautiful) cliffside defense.

Virgil's many-mouthed gateway to the underworld.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

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.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

An Italian hillside ghost town.

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

2300-year-old Roman road connecting the empire.

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

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

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

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

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.