Former headquarters of the KGB.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

Gargantuan home of Russian science.

This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

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

Founded by members of the Tohono O’odham Nation, this one-room joint's James Beard–winning fry bread is light as a cloud.

The world's only teal arches exist in a city that cares more about its aesthetic than an Instagram influencer.

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.

Crafted in 1911, this steam locomotive spent its entire working life in Flagstaff.

A small car graveyard sits in the shadow of the famous Cadillac Ranch.

World's smallest skyscraper, the product of a remarkable con.

Final resting place of Geronimo, Quanah Parker, and the first atomic gun ever fired.

American bison herd descending directly from a Bronx Zoo breeding program that saved the species from extinction.

A luxurious 1880s hotel with its fair share of Tiffany stained glass, Edison electricity, and of course, ghosts.

A sprawling maze of used books piled from floor to ceiling.

This ancient octopus-like tree was saved from destruction thanks to shady reporting.

Ruins of a Carnegie family mansion on Cumberland Island.

If all members were present at the table, a sixth of the world's wealth would be under the same roof.

Interactive modern and vintage submarine equipment, World War II relics, and submarine attire.