Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

This black shoreline is made up of exploded lava particles.

Considered by many to be one of the most dangerous highways in Alaska.

At 11,500 feet in elevation, there is no toilet in the state closer to the sky than this one.

Hidden inside this Arizona fast food franchise is an in-depth exhibit on the famed WWII counterintelligence program.

A mysterious spirit totem at the edge of Navajo lands.

The highest point in Arizona is an oddly snow-topped peak within the otherwise arid state.

This open-pit mine is now an abandoned symbol of Bisbee's copper-mining heritage.

These elusive, isolated rodents evolved into a distinct, locally iconic subspecies.

When it was built in 1929, this historic bridge was the only place to cross the Colorado River for 600 miles.

A monument to the one-armed geologist who led the first documented expeditions through the Grand Canyon.

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

A spiritual vortex among the red rocks in Sedona.

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

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

A nature and cultural preserve named for its multitude of petroglyphs carved by the Northern Sinagua people.

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

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

A planet-hunting astrograph built in the 1920s to seek out the so-called "Planet X" beyond Uranus.

The final resting place of the businessman-turned-astronomer who helped discover Pluto stands near his observatory.

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

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

An old saloon in the West filled with history, and according to some, a few dozen ghosts.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.