The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

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

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

Rome’s legendary peephole vista is also a former Crusader stronghold.

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

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

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

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

Pilgrimage site for star-crossed lovers.

The celebrated eyesore created by starry-eyed sweethearts.

This demon atop the Notre-Dame de Paris looks utterly bored.

A Parisian exterminator's shop whose storefront displays stuffed rats hanging from traps.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This saucy statue once caused outrage among locals.

This plaza is home to a number of works, including Montpellier‘s own Arc de Triomphe.

This historic island prison holds one of the dungeons from the Count of Monte Cristo even though it is a work of fiction.

The world's largest reflecting pool is just two centimeters deep.

This ancient theater was once the home of fierce gladiatorial battles.

Eat the ultimate iteration of Portugal's most beloved pastry.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

The world's oldest bookshop still in operation.

Elaborate tile work in this railway station tells the story of Portugal.