An architectural marvel that spans the Arda River, and has stories of a haunted past.

A Spanish forest is filled with mysterious stone carvings.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

An unrealized dream to wirelessly electrify the entire Earth.

The second-largest (of only two in the world) large particle collider is the underdog of experimental physics.

Beneath the mossy overgrowth covering this once-sprawling campus lies decades of history and the secrets that come with it.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

Empty, but not abandoned, this cavernous Brooklyn loading dock was once considered the largest individual building in the world.

Bowl in splendor, if you're lucky.

San Francisco's newly reopened hands-on science museum.

A museum befitting the city responsible for supplying the majority of the world's LSD.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

A huge musical instrument played by the ocean.

A masterpiece in Golden Gate Park by virtue of the artist’s debt.

340 bicycles, 65 feet high.

Inside an old airplane hangar, friends and strangers alike play on a massive trampoline.

Canyon walls shrouded in ferns.

A "gravitational anomaly" located in the redwood forests just outside of Santa Cruz, California.

Amazing and mysterious Neolithic settlement on Scotland's Orkney Islands.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

A mysterious castle built as a monument to lost love.

Disney World's very first waterpark is now an abandoned ruin being reclaimed by the swamp.

A massive underwater sinkhole made famous by Jacques Cousteau.