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.

Eons ago, a rushing lava river formed this pristine passage through solid rock.

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

Seemingly grown on some other world, these New Mexico rock formations look like a disused science fiction set.

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

The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

Giant origami sculptures tucked into desert scenery beckon passers-by to explore further.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

A museum dedicated to the alleged Roswell Incident.

A blacklight journey through a celestial art exhibit.

High in the Sacramento Mountains, a facility dedicated to studying the sun.

Home of the International Space Hall of Fame.

This is one really big nut.

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

This sculpture perfectly models the molecular structure of a drug that was never produced.

One of the last active volcanoes on the Eastern seaboard.

Bubbling up from deep underground is the warm crystal clear water that fills the Warm Springs Pools, America's oldest spa.

A giant cement churn carries the legacy of American resilience, unity, and greed.

This sweet Southern elixir comes from what may be the oldest grape vine in North America.

A 17th-century bezoar, dirt from an infamous site, and other curios decorate this unusual bar.

An idyllic mineral hot springs facility with a more-than checkered past.

A mountaintop space observatory that is certified dark.