An ancient artistic garden parlor full of hidden water wonders.

Venice's island of the dead.

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

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

A Nesting Doll of Churches.

Virgil's many-mouthed gateway to the underworld.

David Sedaris called it "The greatest shop in the world."

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

Pilgrimage site for star-crossed lovers.

Filled with goldfish swimming in a shallow pool of sea water, this ancient crypt is more wishing well than burial site.

Abandoned medieval hill town.

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

Ruins of a 10th century church tucked away deep in a botanical garden.

The underground sanctuary of a mysterious ancient cult.

Venice's "Island of the Mad."

Stalactites and stalagmites in a beautifully lit cave.

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

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.

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

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

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

This real life asylum of horrors is now an abandoned ruin that hides the unbreakable code to one patient's insanity.

An underground paleo-Christian burial site composed of the remains of several cemeteries and Basilicas.