The largest self-built castle in the U.S., six decades in the making.

The highest bridge in America was built for an almost unnervingly small amount of money.

This razorback ridgeline has doubled as a scenic drive since the early 1900s.

This naturally-sourced hot spring is now home to a clothing-optional resort.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

This Colorado hiking trail provides a small gold mine of abandoned gold mines.

Thanks to a quirk of elevation this gift shop produces magic doughnuts that are found nowhere else on Earth.

Hidden beneath a bridge, this waterfall is known for the large amounts of graffiti painted on its base.

While most of the games in this arcade take quarters, that would have been a small fortune when they were made.

These faux-cliff dwellings allow visitors to climb around on a replica archaeological site.

Strange red rock formations that have been attributed to a higher power for hundreds of years.

The haunted reputation of these abandoned Colorado train tunnels is probably not helped by the terrifying spiked fence.

Victorian "Fancy Craft" Hair Wreaths and Relics.

The moving metal works of one troubled artist can still be viewed on his front lawn... for now.

This grand stone tower was dedicated to a famed American humorist almost by coincidence.

Hidden beyond a kitschy giant beetle is this remarkably sprawling collection of preserved insects.