When zealous marijuana enthusiasts kept stealing the "Mile 420" highway marker, the State of Colorado got creative.

One of few remaining antique carousels with stationary animals in the U.S.

The first graveyard named "Boot Hill" was established in Hays, Kansas, years before better known cemeteries with the same name.

Also known as the Cathedral of the Plains, this church holds the distinction of being one of the "8 Wonders of Kansas."

A wonderful collection of all things Oz is nestled in the heart of Kansas.

A mysterious and terrifying public art goblin seemingly meant to inspire local legend.

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

A cave's rare beauty held a cavernous secret hidden underground.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

A museum dedicated to the alleged Roswell Incident.

A blacklight journey through a celestial art exhibit.

Inside this small museum resides a strange mix of miniature collections passed down over time.

This fast-food outlet is the only space and UFO-themed McDonalds in the world.

The symbol was surreptitiously built into the river bank by German prisoners of war.

Catch two 18-foot-tall ranchers mid-brawl as you drive by on Highway 285.

A planet-hunting astrograph built in the 1920s to seek out the so-called "Planet X" beyond Uranus.

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

The final resting place of the businessman-turned-astronomer who helped discover Pluto stands near his observatory.

A strenuous, unofficial trail leads to spectacular views in one of America's most remote national monuments.

A monument to the one-armed geologist who led the first documented expeditions through the Grand Canyon.

This small interfaith chapel lies not far from the rim of the Grand Canyon.

When it was built in 1929, this historic bridge was the only place to cross the Colorado River for 600 miles.

Archaeologists believe this panel of petroglyphs depicting descending sheep and other figures in Glen Canyon are 3,000 to 6,000 years old.

A sharp bend in a dramatic river canyon cut through red rocks.