The biggest solar telescope in the world helps reveal the secrets of our sun.

America's only nuclear missile silo open to the public.

Limestone caves with spectacular showcase chambers.

A wild west cemetery in Tombstone, Arizona, provides a window into the Old West.

An abandoned quicksilver mining town surrounded by the Big Bend parks.

This museum started as a collection of Manhattan Projects and continues to add exhibits as they are declassified.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

Legends surround this jagged rock formation in the New Mexico desert.

Twenty-seven massive radio antennas on the high plains of New Mexico search for life on other planets.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

Home of the International Space Hall of Fame.

The final resting place of the living embodiment of the famous Forest Service symbol.

The site of Billy the Kid’s most famous escape and the end to the Lincoln County War.

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.

The land is home to swimming ponies and a legendary 18th-century treasure.

The taxidermy remains of the most popular pony in children's literature.

The U.S. Navy’s preposterously detailed mini battleship took 77,000 hours to complete.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

Home of the physician who set the leg of John Wilkes Booth after the Lincoln assassination.

The Virginia farm where John Wilkes Booth met his grisly end is now largely forgotten.

Memorializing an American tragedy of massive proportions.

Steepest flood safety railway in the entire world.

Frank Lloyd Wright's most iconic home dangles over a Pennsylvania waterfall.