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

One of the most important yet well-hidden museums dedicated to the history of medicine.

An incredible menagerie of more than 3 million taxidermied animals at the oldest science museum in Europe.

An ancient artistic garden parlor full of hidden water wonders.

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

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

Virgil's many-mouthed gateway to the underworld.

This abandoned Brutalist treehouse is a hidden architectural relic.

Medieval town turned hippie commune, once home to the secret foreskin of Jesus Christ.

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

A hospital where antique dolls are given new life.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

Crushed coral and crystals give the sand its signature coloration.

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

An Italian hillside ghost town.

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

Thousands of well-dressed mummies below a monastery.

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

A 16th-century horror show built in a lovely Italian garden.

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

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

According to the legend, this structure was built in a single night with the help of the devil.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

This medieval hilltop village was abandoned at the end of the 19th century, after existing for more than 500 years.