These eerie outliers of the lightning bug family glow a mysterious blue color.

Finale of "William Tell Overture" can be heard as drivers pass over grooves in the road.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

Canyon walls shrouded in ferns.

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

This geothermal hot spring hides beneath a slowly growing mineral dome.

The one-time watch house for incoming ships at the Golden Gate now stands abandoned and hidden in trees.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

A reproduction of earth's many biomes.

This woodland architectural installation acts as a camera obscura for the heavens.

One part antique store, one part curiosities hodge-podge.

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

Less a museum than a bizarre fantasy world created by artists and engineers.

A mysterious castle built as a monument to lost love.

Oregon's unexpected high desert, displaying layers of time in a colorful show.

Florida might be at its most surreal in this museum devoted to the famed Spanish artist.

A Bibliophile's Dream.

Breathtakingly blue walls shimmer inside the "Glacier Behind the Town."

The largest earthwork effigy in the world.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

An acoustic anomaly with a mysterious cause.

This knobby, drooping New Orleans oak is a favorite place both for climbing and for meeting giraffes.

A lush green oasis in the middle of Chicago.

Quite simply the largest tree in the world (by volume).