A spiritual vortex among the red rocks in Sedona.

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

Arizona's first government hub is a rustic cabin now preserved as part of a historical museum.

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

An urban laboratory.

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

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

A geological mystery on Camelback Mountain.

The unusual burial monument of Arizona's first governor.

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

The biggest solar telescope in the world helps reveal the secrets of our sun.

Stairs often replace streets on the steep slopes of this old mining town.

Limestone caves with spectacular showcase chambers.

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

After a short-lived attempt to bring America in line with the rest of the world, this road was left in metric.

A reproduction of earth's many biomes.

An off-the-beaten path cave with an underground lake.

Visitors to this public park will also find the ruins of an old western fort.

Miniature art that tells an enormous story.

This southwestern historic site was designed and built by an artist who wanted his work to "feel at home."

This bomb shelter-themed bar has barely changed since it opened.

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

This iconic 1958 tower welcomes air travelers to Tucson with neon-lit letters and architectural style.

Religious statues built because of one man's bargain with God fill this peaceful sculpture garden.