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

The highest point in South Dakota contains the ashes of Valentine McGillycuudy, the "Holy White Man."

One of America's first dinosaur parks gives a window into Depression-era paleontology.

The first declared National Monument in the United States.

A six-ton, 12-foot-tall concrete prairie dog is touted as the largest in the world.

Dedicated to the history of the 1,000 nuclear missiles that once covered the Great Plains.

The highest point in Iowa, while not that impressive to mountain states, has earned its own monuments.

Even Henry David Thoreau found this glacial pothole irresistible.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Dramatic river bend surrounds a natural red-rocked pedestal.

Most-visited and most-photographed slot canyon in the American Southwest.

Oddly shaped rock formation, misassociated with a nearby utopian community.

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

This raised bulls-eye visible from space was the subject of an intense geologic controversy.

The highest point in Connecticut was incorrectly memorialized before surveyors discovered the actual spot.

Home to the deepest rift anywhere on Earth.

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

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

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

This advertisement for talcum powder was painted on the rock face and has since defied removal.

The highest point in Virginia can only be reached by passing through ponies and flowers.

The highest point in Maine is a grand gift to the state citizens that also happens to be one end of the Appalachian Trail.

A precariously balanced rock perches on the edge of a cliff created tens of thousands of years ago by glacial erosion.

These towering spires and glowing walls are carefully crafted from hundreds of thousands of icicles.