The video game-themed street art first popped up in the French city.

This banal Parisian entranceway is not what it seems.

The first green space constructed on an elevated viaduct.

A subterranean shelter remains intact under a busy Paris railway station.

This Parisian café sticks almost exclusively to an ethos of reuse.

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

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

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

A museum of carnival attractions where you are invited to ride the rides.

Abandoned railway line circling the city of Paris.

Notorious artist squat renovated into legal studios.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The grand, column-fronted, sculpture-adorned home of the ambitious digital library.

The remains of a ruined mansion memorialize the 1906 earthquake.

A little known Colombian theme park of giant curiosities.

This picturesque mansion has gone from opulent ruin to nature museum.

Back in 1952, you could get a mushroom cloud chaser with your atomic cocktail.

An essential stop before plundering, BYO Cutlass.

A pair of slides and a tree-lined stair corridor have been an urban oasis for nearly 40 years.

No matter what it might seem like on film, most scenes filmed on a plane are filmed at this LA studio.

A man-made island in scenic San Francisco Bay.

San Franciscans leave gifts and messages for the magical beings that live behind the tiny, mysterious door installed on a tree in Golden Gate Park.

The randomness of this wall of lava lamps helps encrypt up to 10 percent of the internet.

A modern mechanical planetary system, part of a 10,000 year clock.