A Norwegian-born sculptor created these soaring guardian angels at the entrance to Hoover Dam.

These markers are used to document elevation changes around the famed dam.

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

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

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

Sleep where gangsters fell amidst smoke and flame, with nary a bullethole to show for the legendary struggle.

In Tucson a giant metal snake helps pedestrians cross a busy highway.

The world's largest military aircraft cemetery.

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

Take a monster truck tour around an ostrich farm in the middle of the desert.

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

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

A geological mystery on Camelback Mountain.

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

The first permanent memorial to a unique secret weapon of World War II.

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

Once a year, at exactly 11:11 a.m., this monument comes to life.

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

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

An urban laboratory.

A Wild West jailhouse that slid down the mountainside.

This oversized flute-playing Ancestral Puebloan deity is also a landmark of Southwestern kitsch.

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

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