The Giant Lemon of Lemon Grove.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

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

One man's ambition created this psychedelic log home.

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

This prison-turned-museum is a remnant of the Old West's grizzly, violent past.

Devilish landscape, once cinema home to giant alien bugs, now derelict roadside attraction.

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

The first declared National Monument in the United States.

This geodesic gallery holds a collection of painted spheres that make traditional canvases look lazy by comparison.

This replica stave church looks like a piece of Norway was simply plopped down in South Dakota.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

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

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

The high point on the 16th president's eponymous roadway is marked by a massive version of his head.

A monument to the egos of two railroad magnates that fell into decline along with their careers.

Miraculous tree that seems to sprout out of solid rock.

One of the smallest towns in the United States.

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

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

Massive still life just off the highway in Kansas.

Exact replica of the ancient monument, but much, much lighter.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

"Not too many people can say they've had a nuclear bomb dropped on them, not too many would want to." — Walter Gregg.