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.

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

100 year tradition of fist fights, marked by marble footsteps.

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

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

A floating cat sanctuary on an Amsterdam canal.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

This charming cobbled backstreet is the most Instagramable street in Paris, much to the residents' annoyance.

The first green space constructed on an elevated viaduct.

Paris' fabled purveyor of exotic taxidermy and natural history curios.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

Abandoned railway line circling the city of Paris.

This massive library holds what was once the largest book collection in the world.

A museum on the history of Paris, including a set of Napoleon's toiletries, Proust's room, and relics of the Revolution.

Notorious artist squat renovated into legal studios.

A whimsical brother of the nearby Fallen Angel statue takes the falling part quite literally.

Thanks to an acoustic anomaly, this unassuming stone bench has heard one hundred years of secrets.

Earth's rocky history has rarely glittered so brightly as it does in this Spanish museum.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

Of course Salvador Dalí lived in a castle...

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.