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

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

This striking public art installation is suspended above a public park, designed to gently move in the breeze.

A self-built castle made by a mysterious man.

Every Christmas, one Arizona city makes the most of its dry climate by creating an arid desert tannenbaum.

This collection of vintage signs reflects the long and colorful history of this Arizona town.

Rumor had it that these concrete crosses scattered across the Arizona scrubland helped align spy satellites. (They didn’t.)

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

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

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

Race through the maze, get your name on the sign.

This World War II-era bunker is now packed with posters and props from movies and TV shows filmed nearby.

An authentic replica of an Asian temple and garden hidden amongst the natural beauty of Hawai'i.

Joseph and Victor Stanzel were Texas farm boys who built a model aircraft empire.

The saga of the massive nut begins and ends in Texas.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

Explore a misty river canyon from a metal bridge system.

During World War II this was the site of an "honor camp" used as a prison for draft dodgers, Native American conscientious objectors, and Japanese-Americans—including a man who brought his case against the camp to the Supreme Court.