Clean, cold drinking water flows from a nondescript pipe in a roadside rock face.

This narrow canyon has been carved by the river over thousands of years into spectacular and curious forms.

Even Henry David Thoreau found this glacial pothole irresistible.

This gorgeous beach hides behind two headlands in Oregon's Ecola State Park.

The last physical evidence of the Lewis and Clark trail is one of their autographs etched into this giant rock.

This symbolic piece of New Orleans architecture is also home to a few ghastly stories.

A collection of oddities including Dr. Kevorkian's suicide device, the Thanatron.

The final resting place of New Orleans' most famous voodoo priestess.

Population: 1.

A popular rock that acted as a waymarker for American pioneers.

Long before guestbooks and hotels, frontier travelers signed their names on this rock face.

Creek water that starts here has a 50/50 chance of ending up in the Atlantic or the Pacific.

A miraculous natural phenomenon known as "the spring that breathes."

An architect's childhood fantasy treehouse made real.

Native Americans built this circle of stones, which was used to predict astronomical events.

The largest hot spring in the United States is, as the name suggests, a stunning show of natural color.

A beautiful geyser under environmental threat.

The first declared National Monument in the United States.

The granite monument is engraved with the image of the talking horse's head coming through a barn door.

Along the historic Mother Road is an old gas station with a secret counterfeiting past.

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

A mysterious light floating in the trees of Arkansas may be a piezoelectric effect.

The final resting place of infamous outlaw Clyde and Marvin Barrow.

The final resting place of an outlaw, whose legend grew after death.