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

A forgotten "city of water" underneath the famous Trevi district.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

A statue representing a lost Roman profession that was vandalized for centuries.

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

Romans decided this 16th-century "talking statue" was so ugly, they named it after a primate.

A deep mark on the remains of a Roman temple, believed to be left by a legendary warrior.

This hydrochronometer was invented by a Dominican monk and is a prime feature in this garden.

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

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

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

The Italian revolutionary's legendary wife is portrayed on horseback waving a gun and holding her child in this memorial on the Janiculum.

The charred, dead skeleton of an oak tree is said to have consoled a dying 16th-century Italian poet.

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

Rome is now home to a stunning food museum and library.

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

Originally a leper colony, the island is now an Armenian monastery that's home to an incredible manuscript library and eclectic museum.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Some of the smallest works of art in existence.

This small and serene place for quiet reflection on Staten Island was built in China based on the gardens of the Ming Dynasty.

Portugal's National Pantheon has a history of curses, collapses and financial problems.

The resting place for anonymous victims of the Danube's dark waters.

A garden in Lisbon filled with giant porcelain creatures.