Renaissance hospital featuring a rotating door into which unwanted babies were dropped.

Anatomical cabinet holds unexpected treasures.

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

A dismembered holy head stares out from her beautiful reliquary at the St. Dominic Basilica.

"Stairs of the Turks", a chalky white cliff eroded conveniently into stairs, allowing for easy pillaging.

This winding road through an Italian canyon may be the most scenic drive in the world.

This hill made entirely of ancient Roman jars was simply a garbage dump to the people of the time.

One of the world’s smallest bars, just 13 square feet, is brimming with speakeasy flair.

The Pope’s secret escape route.

Romans built the world's tallest artificial waterfall in 271 BC.

The giant skeleton sculpture is surprisingly well-traveled.

Gigantic mosaic sculptures of the figures on Tarot cards fill this colorful Tuscan garden.

Eco-village hidden in the foothills of the Alps that created a massive system of psychedelic underground temples.

This half-finished "city of toys" was almost Italy's own Las Vegas.

This Tuscan lake hides a 13th century town that is still visible when the water recedes.

This picturesque Umbrian city has a subterranean side that has long remained hidden.

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

A hospital where antique dolls are given new life.

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

Virgil's many-mouthed gateway to the underworld.

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

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

This Italian foot path winds through the mountains via 52 individual tunnels.

A complex, nine-layer maze on the grounds of a Venetian doge's playground.