A dangerous narrow-gauge railroad once traced a route through this striking canyon.

A beautiful geyser under environmental threat.

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 only road through the heart of Glacier National Park.

Spectacular views await visitors to this lake.

The first declared National Monument in the United States.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

A phenomenal assembly of pueblos in New Mexico is the most complete example of ancient ruins north of the border.

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

This historic national park is covered in the stunning ruins of red rock pueblos.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

A house carved into a rock in the 1940s.

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

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

One of the world’s largest collections of petroglyphs records 2,000 years of human activity.

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

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

A natural formation that resembles a camel resting in the New Mexico desert.

A Portland legend tells of small green archers shooting random passersby with visionary arrows.

A crumbling island fortress that seems to be covered in a field of stone crosses but is simply incomplete.

Montmartre's sole surviving windmill became an iconic landmark for 19th-century painters, artists, and bohemians.

Lemon Grove, California is known for its giant lemon...and mummified bodies.

The last living thing to come out of the rubble after 9/11 is now a symbol of hope and resilience.