The grandson of a Kiowa chief created what has become the iconic symbol of a city on the Plains.

The first "Hut" was actually a small brick building.

After retiring, Gary Pendergrass turned his yard into a wonderland of outsider art.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

This Colorado gallery is primarily for cars, but its collection also includes quilts, pottery, and more.

This marker identifies the location where three states converge.

Thanks to a loophole in property ownership, this alleyway has become a cacophonous street gallery.

The oldest extant wooden jail in South Dakota and possibly the United States. 

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

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

An experimental, automotive replica of Stonehenge.

This erect, phallic geological spire wasn't always named so domestically.

This museum showcases the history and contributions of the U.S. Army to the medical industry, both on the battlefield and off.

Foragers once flocked to this big beautiful bayou to hunt for pearls.

Crumbling hotel echoes with the sounds of the '30s.

A spring-fed pool so deep it's used for scuba diving as well as swimming.

A Texas cave network is home to some of the world's most spectacular-looking and bizarrely named mineral formations.

The Grand Canyon of Texas.

A collection of 100 brains preserved in jars on the UT campus.

This abandoned building made of petrified wood was once a hotspot for buying moonshine.

The world's tallest statue of an American hero.

A tribute to the little-known group of women who were the first ever to fly aircraft in the U.S. military.

An abandoned, decaying sculpture garden built by an eccentric physician in the 1920s now looks more like a forgotten cemetery.

Two massive and unstable sinkholes are yearning to unite, and their consummation could be catastrophic.