A geological mystery on Camelback Mountain.

A towering bronze statue memorializes the founding father of postwar American conservatism.

Come for the pizza, stay for a performance on the world's largest theater pipe organ.

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

The "Father of Arizona" tried to build a Zoroastrian fire temple on the hill where he's now buried.

These free-roaming horses were once destined to disappear from the land.

A historic jail preserves etchings from over a century of incarcerated people in a town with a rough and tumble past.

The largest natural travertine bridge in the world is nestled in a small canyon in central Arizona.

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

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.

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

An artificial crater field that trained astronauts for lunar exploration.

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

An homage to everyone's favorite prehistoric cartoon family.

The self-proclaimed gateway to the Extraterrestrial Highway.

An eatery for UFO seekers on the Extraterrestrial Highway.

This sign designates the road that leads to the infamous Area 51.

A Saint Nicholas-themed ghost town in the Mojave desert.

Brightly colored 30-foot-tall totems light up the desert sky just outside Las Vegas.

The bullet-riddled wall from the St. Valentine's Day Massacre, bloodstains enhanced for your viewing pleasure.

Flashy signs from Las Vegas’s past find their final resting place at this unusual graveyard.

This airfield played a key role in both World War II and the Cold War.

One of the largest free-standing structures ever built, this dirigible hangar is now simply a giant skeleton.