Colorado's only active volcano last erupted around 4,000 years ago.

Once named the “world’s oldest gas station” due to its unusual construction material.

Only a few signs remain of the buried Colorado mining town that supplied the uranium for the first atomic bomb.

The site of the gruesome massacre—and maybe cannibalism—of five men, a tragedy that made Alferd Packer infamous.

The decaying ruins of a failed mining company’s water diversion project cling to the side of a desert canyon.

The site where a nuclear bomb was lowered over 8,000 feet underground and detonated as an experiment in natural gas extraction.

Final resting place of a 19th century gold prospector and convicted cannibal.

Metal water storage tank turned ethereal concert hall.

The largest source of fossilized insects anywhere.

This once-popular otherworldly landscape was formed by one of the largest volcanic eruptions in history.

Every year, festive decorations appear on this juniper tree located in the median strip of a busy highway.

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

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

Archaeologists believe this panel of petroglyphs depicting descending sheep and other figures in Glen Canyon are 3,000 to 6,000 years old.

A memorial to the firefighters who died in an industrial disaster is housed in a small public park.

In 1975, a forestry worker in Arizona claimed to have been abducted by a UFO.

This mesmerizing and surreal landscape features intricate patterns of white and red sandstone.

More than 25 fully functional scale replicas of famous lighthouses dot the shores of Lake Havasu.

A scrap-metal sculpture recalls an infamous 19th-century camel.

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.

This comprehensive collection features Native American artifacts dating back centuries.

This memorial pyramid marker honors one of the United States Government's first official camel riders.

The largest copper mine in Arizona, this enormous open pit emerges from the hills like an alien landscape.