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

A haunting collection of the vanished and disappearing natural world.

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

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

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

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

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

Sample specialties from Xinjiang at this Shinjuku neighborhood gem.

This museum showcases the art of ancient sword-making.

Dedicated to the armor and weapons used by the legendary Japanese warriors.

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

The history and future of cannabis.

This spooky statue sits outside a famous Prague theater.

A series of playful yellow penguins share a serious message about the environment.

A saintly relic hidden in a Prague church basement.

This walkway is so narrow it needs its own light to stop pedestrian traffic jams.

An Orwellian sculpture with eyeball cameras watches passersby.

A mocking tribute to the past and modern leadership of Prague.

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

Street artists transformed an abandoned air vent into the beloved Star Wars robot.

This doorless 20th-century elevator doesn't stop or slow down.

This artificial cave looks like something out of a fairytale.

The risqué mixed-media sculptures are supposedly a metaphor for Czech politics.

Countless grotesque faces stare out from this eerie Prague art wall.