After a short-lived attempt to bring America in line with the rest of the world, this road was left in metric.

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

This church on a Tohono O'Odham reservation has stood since 1797.

The fading, forgotten remains of a once bright and booming factory.

One of the oldest Mexican restaurants in the United States air-dries its trademark beef in a dangling outdoor cage.

More than a century old, this trading post resides in the Navajo Nation.

See massive fossils that are over 200 million years old in northeastern Arizona.

This historic national park is covered in the stunning ruins of red rock pueblos.

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

This public square capitalized on a single Eagles reference to bring some life back to an Arizona town.

The story of Two Guns, Arizona could easily be described as a Shakespearian tragedy on Route 66.

A pair of giant roadside arrows are all that remains of a former Route 66 trading post.

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.

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

A reproduction of earth's many biomes.

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

On the outskirts of a reborn ghost town, a decaying post office remembers the bad old days.

A Wild West jailhouse that slid down the mountainside.

This sinkhole in the Arizona desert is filled with carbonated, arsenic-rich water

Take a monster truck tour around an ostrich farm in the middle of the desert.

A stone pillar marking the location of the westernmost battle of the American Civil War only honors one side of the conflict.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.