The biggest solar telescope in the world helps reveal the secrets of our sun.

An Arizona museum with a collection of pharmaceutical oddities, including a jar of a gangster's chewed gum.

The world's largest rose bush has literally outgrown the pioneer museum it was planted behind.

This Route 66 classic sports a giant fiberglass rabbit that you can ride.

One of the world's largest telescopes, stares into the night sky with two huge mirrors.

An artificial crater field that trained astronauts for lunar exploration.

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

Ancestral Puebloan ruins, natural arches, and box canyons abound in this seldom-visited corner of Monument Valley Navajo Tribal Park.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

Limestone caves with spectacular showcase chambers.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

A Saint Nicholas-themed ghost town in the Mojave desert.

America's only nuclear missile silo open to the public.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

Dramatic river bend surrounds a natural red-rocked pedestal.

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

Rippling sand dunes frozen in the Arizona rock.

One of the few remaining carousels built by master amusement park carver Charles I.D. Looff.

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

An inconspicuous footbridge beloved by San Diego locals.