Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

Secret refuge and museum of the Duke of Florence.

This centuries-old Italian chapel hangs midway down a sheer cliffside.

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

The abandoned "Ghost Mansion" was left to decay in the mountains of Northern Italy.

The remains of a town so thoroughly destroyed by French forces that the citizens simply left.

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.

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

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

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

Five candy-colored villages on the Italian Riviera.

An Italian hillside ghost town.

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

Abandoned medieval hill town.

Stalactites and stalagmites in a beautifully lit cave.

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

This 16th-century monastery has been turned into a surrealist architecture compound.

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

Venice's "Island of the Mad."

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

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

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

This 170-year-old Swiss guesthouse built into the side of a mountain is best accessed by a cable car.

Legend says that this short Canadian tunnel still holds the dying screams of a girl who burned alive.