The only royal palace on U.S. soil has been a territorial capitol, a military headquarters, and a prison for a queen.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.

What remains of the summer palace of King Kamehameha III.

A Hawaiian stairway to heaven—that you can't climb.

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

The air force base preserves its scars from the Japanese attack on Pearl Harbor.

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

This ancient Hawaiian henge may have been an early star chart.

Earth's tallest volcano is sacred to Native Hawaiians, and home to a dozen world-class observatories.

The "World's Largest Underground Business Complex," a 55,000,000-square-foot city underneath Missouri.

Curious cave that stays a cool 56 degrees all year long.

Erosion and time have created a naturally-formed water park.

Once an ambitious nature spa, these forest ruins now provide a serene monument to failure.

The United States's largest hand-dug well is topped with a state-of-the-art museum.

This otherworldly church spire reaches up toward the heavens.