A fairy tale castle in modern Rome.

This beautiful park on the outskirts of Rome protects the ruins of two colossal ancient aqueducts.

Jesus' footprints and the first catacombs in the world.

The glowing blue Nymphaeum of Emperor Tiberius.

Sitting on an Italian hilltop is this surreal fortress built by the mad inventor of electrohomeopathy.

Venice's "Island of the Mad."

Architectural monsters are devouring this palace's every door and window.

Geothermal waterfalls in Tuscany.

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

The final resting place of the poets Shelley and Keats.

Thousands of well-dressed mummies below a monastery.

An ossuary built in 1210 to collect bones from the Ospedale Maggiore of Milan.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

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

Stalactites and stalagmites in a beautifully lit cave.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

According to the local folklore, the myriad colors of this lake are the result of a lovelorn wizard's blunder.

The skull of the patron saint of lovers lies in the Basilica di Santa Maria in Cosmedin—maybe.

2300-year-old Roman road connecting the empire.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

Renaissance villa and gardens complete with a tormented colossus.

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

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

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