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

An early 20th-century jail not far from the infamous Tombstone, Arizona.

The former home of the army detachment that captured Geronimo.

The Grand Canyon’s original airport, which once welcomed pilots like Amelia Earhart and Charles Lindbergh, lies abandoned.

This tucked-away cemetery is the final resting place of a prospector who uncovered one of the largest gold mines in Arizona.

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

The lobby of this hotel near the U.S.-Mexico border features a stained-glass mural that measures 42 feet long and 6 feet tall.

One of the best-preserved ghost towns in Arizona speaks to the difficulties of establishing mining towns in the 19th century American West.

This fireplace-turned-monument pays tribute to the assassinated U.S. president.

Previously a hot spring, this park remains a site of unique history, wildlife, and geology.

These petroglyphs created by ancient Arizonians have withstood centuries of exposure to the elements.

An excursion train traverses a picturesque red-rock canyon along the Verde River.

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

The remains of a boarding school designed to forcibly assimilate Native American children.

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

Two geoglyphs that are truly unique to North America.

This Native American settlement dates back to the Pueblo II period.

A colorful, century-old cemetery of the Yaqui Indian Tribe hidden amid the suburban sprawl of Tempe, Arizona.

Red sandstone structures dominate this landscape, which has been inhabited for some 5,000 years.

Petroglyphs, bird watching, and a 100-year-old Ranch in one location.

One of the largest open-pit copper mining operations in the entire country.

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

A mistaken marker makes an erroneous claim along the historic Old Divide Road.

Some 10,000 works of ancient rock art cover these volcanic basalt outcrops near the Gila River.