Colorful and chaotic stacked hotel in North Holland.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

At the center of London’s oldest roundabout stands an obelisk that was erected in 1771, but spent several decades elsewhere.

Giant, friendly pelicans in Central London, the most unlikely of places.

The Argonaute submarine was the French navy's pride and joy in the 1950's.

César Baldaccini's iconic sculpture of a 40-foot thumb stands tall in La Défense.

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

Montmartre's sole surviving windmill became an iconic landmark for 19th-century painters, artists, and bohemians.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

Paris' linguistic guide to the international language of, yes, love.

What looks like a normal building is really a hollow facade hiding a subway vent.

France's most famous cemetery, with some of its most curious tombs.

An immersive projection art installation uses sound, scale, and light to take visitors inside classic works of art.

The headless bodies of more than 1,300 guillotined victims of the Reign of Terror are buried here in mass graves.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

A tribute shrine where the Space Invasion street art movement started.

In this Parisian garden's grotesque former life as a zoo it fed exotic animals to the bourgeois and put humans on exhibit.

"In the Dark" Restaurant in Paris offers dinner in complete darkness.

A series of abstract, silly sculptures represent the works of a great modern classical composer.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

For more than a century, Parisians have come for affordable dishes in a grand converted train station.

The first green space constructed on an elevated viaduct.

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

After immigrating to Paris in the 1970s, two brothers from Laos built a grocery store empire.