The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

An abandoned village that doubled as "The Hunger Games"' post-apocalyptic wasteland is up for grabs.

This restaurant serves wood-fired fare served in a natural cave with a live spring.

This century-old roadside attraction is full of bizarre rock formations.

A permanent outdoor art installation made up of more than 100 mushroom-shaped lights.

North Carolina's only restored fort from the French and Indian War.

A 315-foot spire jutting out from the Blue Ridge Mountains makes for breathtaking views.

Practice your Dirty Dancing lifts in the manmade lake where Johnny Castle himself did.

Golden Gate Park's historic collection of plants.

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

A library and museum dedicated to typography.

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

A tiny theater hidden in an alley plays a constant stream of short silent films for anyone willing to peer through the peephole.

This grinning pup statue is all that's left of what was once a ubiquitous Bay Area diner chain.

This surreptitious shop is only open five hours per week.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

This Asheville chair museum wants to revive a dying art.

These eerie outliers of the lightning bug family glow a mysterious blue color.

A wedding chapel, vintage clothing shop, and bar all under one roof.

The humble horn finally finds a place in the sun.

A cabin completely covered in coffee mugs, where visitors are welcome to leave one of their own—if they can find an empty nail.

Despite being burnt down multiple times, the ruins of this South Carolina church are still standing.

One of the world's tallest Ferris wheels takes visitors high above Las Vegas in a spinning party room.