This public space is speckled with the eerie remnants of a defunct amusement park.

"Dark Sky Park" is heaven on Earth for astronomers, one of the rare U.S. locations with no artificial light pollution.

Home of a 28-foot tall stalagmite known as the War Club.

A historic coal mine that doubles as a museum and tourist attraction.

An abandoned asylum incorporated into a college campus.

The overgrown remains of an old rail bridge rise above the valley like ancient Greek ruins.

There is beauty and history in the ruins of this former company town.

This former tuberculosis treatment facility now stands at the center of a public park.

A castle built by an eccentric medieval enthusiast in rural Ohio.

Rare recess caves fill this unbelievably beautiful Ohio park.

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

A small oasis not far from downtown Moab.

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

A crack flared at the base provides a pathway completely through a sandstone ridge near Moab.

Once connected to the outside world by a single train track, this ghost town is looked after by the National Park Service.

Hikers can still stroll beneath the long conveyer of this abandoned mining facility hidden in a West Virginia river gorge.