Rippling sand dunes frozen in the Arizona rock.

The fifth-longest natural arch in the world, and the longest outside China.

This bridge is haunted by the ghost of a distraught mother.

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

A small storefront museum explores the history and myth of West Virginia's famous urban legend.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

Away from the crowds of fishing enthusiasts, take a hike deep into the woods and journey into an eerie darkness.

It's safe—and permitted—to walk across these twin natural sandstone arches.

A lush green oasis in the middle of Chicago.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

The maximum security facility was once thought to have "the bloodiest 47 acres in America."

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

A historic house in St. Louis was plagued by a series of suicides committed by family members involved in a successful brewery.

Most comprehensive museum in America devoted to one ethnic group.

In rural Iowa, an imported 19th-century windmill overlooks an unlikely enclave of Danish culture.

An Iowa town celebrates its heritage with the tallest working Dutch windmill in North America.

An old town theater converted into a celebration of the hobo legacy.

For just a few bucks, this Iowa funicular will let you feel like an 1800s fat cat.

A warning to the weak-kneed: This narrow bridge does its swinging eight stories high.

A number of gruesome unsolved murders have turned this simple home into a morbid tourist trap.

A half-mile long and three stories high, this bridge over the Des Moines River Valley mimics a descent into a mine shaft.

Chilly air billows out from the entrance of an abandoned mine on a steep hillside, providing a refuge for Ice Age fauna and flora.

A mysteriously dark cemetery monument fuels stories and legends galore.

Home with Gothic windows featured in a famous painting.