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

This prehistoric sinkhole lured exclusively male mammoths to their death, much to the delight of science.

Around half a million years ago, these magnificent columnar basalt cliffs were formed from cooling lava.

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

A beautiful geyser under environmental threat.

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

An architect's childhood fantasy treehouse made real.

This rustic old building is said to be the most photographed barn in America.

One of Mexico's least-visited archaeological sites is tucked away inside a theme park.

The largest retailer of seashells in the world.

One-time winter retreats of prolific inventor Thomas Edison and his friend Henry Ford.

This small beachside park commemorates the possibilities of discovery.

A building so large that it has its own weather.

A 24-hour vending machine restocked daily with homemade full-sized pecan pies.

Locals dubbed it the "Owl Building" because of its bird-like appearance.

Legend has it the commander of the defenders drew a fateful line in the dirt with his sword just before the final battle.

An ivy-covered arch bridge dedicated to Tejano music singer and legend Rosita Fernandez.

Three hundred years of preserved Spanish colonial history in San Antonio.

The highest point in Tennessee, Clingmans Dome bears witness to the ravages of one type of insect.

Cherokee alphabet, proof of ancient North American Jews, or just a hoax?

Some North Carolina Cherokee have been keeping their history alive for decades with a single play.

The highest point in South Carolina was once owned by an energy company that neglected it but now the state is taking it back.

This granite rock face is named for the magnificent reflection that occurs when the sun hits it just right.

Who needs fancy modern water slides when this giant North Carolina rock works just as well?