Storage units with a wartime past.

The highest point in South Dakota contains the ashes of Valentine McGillycuudy, the "Holy White Man."

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.

Other-worldly rock formations and ancient fossils abound in this unique stretch of Nebraska badlands.

The largest dinosaur trackway in North America is tucked away among this canyon's ghosts and archaeological gems.

This unassuming layer of clay boasts an out-of-this-world origin story.

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

Roaming bison and a spectacular view at the highest point in Nebraska.

In the early 1900s, hundreds of Black Americans found opportunity in this now-abandoned rural community.

In one of the hottest parts of the Mojave Desert, shallow bedrock forces the typically dry Mojave River to the surface in this canyon, providing a vital oasis for humans and wildlife.

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

The stone-covered graves lie within the ruins of an Old West ghost town.

An early 20th-century jail not far from the infamous Tombstone, Arizona.

With more than 2,000 pieces, this is world's largest collection of artwork inspired by Leonardo da Vinci's 'The Last Supper.'

The lobby of this hotel near the U.S.-Mexico border features a stained-glass mural that measures 42 feet long and 6 feet tall.

Hike the unusual hoodoos and rock formations that form this little-known natural wonder.

A volcanic tunnel illuminated by natural skylights offers a shaded respite from the desert sun.

One of the ghostly stops along Route 66.

A Bhutanese temple gifted from the isolated Himalayan kingdom is now a surprising cultural gem located at the University of Texas at El Paso.

A rattlesnake museum showcasing over 30 species, in a century-old building that used to be the general store in this tiny West Texas town.

Minimalist modern art on a repurposed military base in rural Texas.

A World War II officers' club features Old West murals painted by German POWs.

An abandoned mine where dreams of quicksilver trickled away over 75 years ago.