The glowing blue Nymphaeum of Emperor Tiberius.

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

Venice's "Island of the Mad."

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

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

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

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

2300-year-old Roman road connecting the empire.

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

The underground sanctuary of a mysterious ancient cult.

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

Stalactites and stalagmites in a beautifully lit cave.

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

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

Thousands of well-dressed mummies below a monastery.

Geothermal waterfalls in Tuscany.

The middle finger of modernity.

At the crypt of St. Mary of Eulogies and the Dead you are left alone to ponder mortality among piles of skulls.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

A master of trompe-l'oeil creates a stunning, tourist-fooling dome out of a flat ceiling.

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

Architectureal fantasy quarter of Rome.

A submerged archeological park still holds the wonders of a Roman Sodom.

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