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

The biggest drug trafficking passage between Mexico and the U.S.

Mysterious glowing orbs float through the desert night.

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

Strange red rock formations that have been attributed to a higher power for hundreds of years.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

Explore some of the most unique vehicles in history along with a cast of unsettling mannequins.

The highest paved road in North America winds its way up Mount Blue Sky in Colorado to an altitude of 14,130 feet above sea level.

Once a favorite playground for the world's most illustrious guests, Hotel Nacional's secret weapons and bunkers reveal a more menacing side to its golden history.

Roam the cradle of the Cuban Revolution with life-sized dinosaurs.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

A house carved into a rock in the 1940s.

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

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

The longest living non-clonal organisms on Earth.

Officially named the "Loneliest Road in America," this barren stretch of Nevada road offers almost nothing but sky and open fields.

Surrounded by a hundred mile radius of billboards, Little America is a roadside attraction whose primary appeal is hospitality.

Come for the speed, leave in love with the desert.

Home to the deepest rift anywhere on Earth.

The only road through the heart of Glacier National Park.

An architect's childhood fantasy treehouse made real.

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

A beautiful geyser under environmental threat.