A landscape of massive spherical boulders are the main attraction in this Kansas State Park.

A cannon designed to fire an atomic warhead.

The United States's largest hand-dug well is topped with a state-of-the-art museum.

Small plaque marks the spot, but the true center is located about half a mile away on a private pig farm.

One of the Eight Wonders of Kansas and the first official National Natural Monument these stark formations look like nature's Stonehenge.

Curious rock formations in a tiny Kansas state park.

This razorback ridgeline has doubled as a scenic drive since the early 1900s.

When zealous marijuana enthusiasts kept stealing the "Mile 420" highway marker, the State of Colorado got creative.

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

The highest bridge in America was built for an almost unnervingly small amount of money.

The largest source of fossilized insects anywhere.

Abandoned silver mine strewn with wrecked and twisted structures.

This "zoo" is a cross between a junkyard and a sculpture garden, featuring animals you won't see anywhere else.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

These black pillars of volcanic basalt seem to call mountain climbers with an unbreakable siren song.

Sweet Willy, at 30 feet tall, is the world's biggest beagle.

Home to the deepest rift anywhere on Earth.

The scuba diving training facility was named for the steam that rises from the cave's chimney.

A community of collapsing homes more than a mile out from the Florida coast.

An abandoned vacation home spent a decade taking on legends. It's now taking on water.

Stay in a room with a view... of the bottom of the ocean.

An underwater city for the dead.

Tucked away on an empty wooded lot in suburban Oklahoma City lie the remnants of an abandoned circus camp.