This Prescott institution is widely considered the oldest bar in Arizona.

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

Ninety feet off the valley floor is an ancient dwelling put under protection of the U.S. government by Teddy Roosevelt.

An urban laboratory.

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

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

This oasis-like spring in the Sonoran Desert is home to unique, endangered species.

The massive, incredibly rare instrument is over 11 feet tall with a range so deep it goes lower than humans can hear.

A disciple of Frank Lloyd Wright built an experimental, partially underground home in the desert.

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

A museum and tribute to a brave profession.

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

Florence's historic adobe county courthouse was turned into a historic site that honors one of Arizona's most prominent political leaders.

The world's largest rose bush has literally outgrown the pioneer museum it was planted behind.

The Jewish section of the famous Boothill Graveyard was abandoned for nearly 100 years.

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

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

At an isolated roadside rest area stands a monument marking where famous Western star Tom Mix died in 1940.

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

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.

A reproduction of earth's many biomes.

This small hill features the most notable collection of petroglyphs in Saguaro National Park.

Legend says train robbers stashed their gold within the depths of this unusual cave.