This hidden stream beneath Indianapolis makes an appearance in the best-selling novel "Underground Airlines."

The hike through a narrow river flanked by the 2,000-foot-tall walls of Zion Canyon is one of the best in the world.

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.

Giant pinnacles in the sun-scorched lands of Southern Utah have been nicknamed "white ghosts."

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

Ancient human, animal, and geometric figures drawn in the earth.

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

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

Don't blink or you'll miss it.

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

A stealthy Apache hideaway that became the haunting site of a mass grave.

In this small Phoenix taxidermy emporium, you can find everything from a squid in a jar to a freeze-dried toad.

Outsider Art Community.

Stripes of flowers bloom each spring in a 50 acre rainbow of color.

This little blue house pokes out over the campus of UC San Diego, seven stories high.

San Diego's most historic and haunted home.

An inconspicuous footbridge beloved by San Diego locals.

A sculpture of the famous photograph stands on San Diego's "Greatest Generation Walk."