Population: 1.

Around half a million years ago, these magnificent columnar basalt cliffs were formed from cooling lava.

This haunted hotel built on natural springs once served as a hospital for a quack doctor promising a cure for cancer.

An extravagant western hotel where every floor is the "ground floor."

One of the most acclaimed eateries in Arkansas is a two-table diner on the ground floor of a family home.

This historic hotel on Bathhouse Row in Hot Springs National Park has a storied history of gangsters and baseball greats.

A restored schoolhouse was once a vital part of the Black mill workers community in Arkansas.

See massive fossils that are over 200 million years old in northeastern Arizona.

On the outskirts of a reborn ghost town, a decaying post office remembers the bad old days.

Limestone caves with spectacular showcase chambers.

Ancient pueblos built into the base of a natural canyon wall.

The largest natural travertine bridge in the world is nestled in a small canyon in central Arizona.

This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

An artificial crater field that trained astronauts for lunar exploration.

Witnessing the might of this dessert-colored desert waterfall is a rare, powerful treat.

A living snapshot of a different time in America is preserved and maintained by a community of volunteers.

A secret fresh water spring for animals and humans alike hidden along the most famous road in the United States.

This immigrant bridge once spanned the Thames but is now a fixture of an Arizona city.

The highest point in Arizona is an oddly snow-topped peak within the otherwise arid state.

A partial tunnel blasted into a steep ridge is all that remains of a failed railway across Arizona.

A $100,000 tumbleweed decorates an Arizona park and ride that got its priorities a bit tangled.

More than 300 years ago, a revolt at this Hopi pueblo shaped the future of the American Southwest.

The eroded core of an ancient volcano is now accessible by a short hike.

Founded by members of the Tohono O’odham Nation, this one-room joint's James Beard–winning fry bread is light as a cloud.