Allowing humans and fish alike to migrate from freshwater to saltwater and back again.

Now housed in a museum, this giant pink elephant stood in downtown Seattle for more than 60 years.

The tech giant built three enormous glass orbs in Seattle so employees could work inside a rainforest greenhouse.

A large AIDS Memorial Pathway art installation provides a moment for quiet contemplation in this public park.

A wall of chewing gum moonlights as collective art.

A walk through the historic city center, under the streets of Seattle.

This working class sculpture pounds his hammer all the livelong day.

A massive, gleaming sea turtle with a rider atop its shell looks out over the horizon.

This whimsical statue dumps water on its head to symbolize knowledge flowing into his brain. Or maybe booze.

A nuclear reactor created for Eisenhower's "Atoms for Peace" campaign is now used for research at a Dutch university.

These tenacious 14th-century towers defied demolition and are now a fairytale vacation rental.

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

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

It's just another skyscraper, but it's shaped like '90s cell phone.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

Modest by day, illuminated majestically at sunset.

India’s only Brain Museum displays over 200 fascinating ways that your brain might kill you.

This narrow Ghent alleyway is an officially sanctioned street art tunnel.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

A giant bug impaled on a 75-foot-tall needle.

A statue of the second-tallest Dutchman in history.

Fantastic views and thousands of love locks.

Why walk on this historical site when you can zoom down instead?

This probably wasn't what Mao had in mind.