Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

This museum devoted to the gothic author holds such interesting ephemera as his socks and walking stick.

Rare recess caves fill this unbelievably beautiful Ohio park.

A popular swimming hole that hides one of America's most deadly diving spots.

Mysterious ancient boulder carved with petroglyphs in the mountains of Western North Carolina.

The eccentric mansion of one of the most popular horror authors of modern times.

This lake in the Cascades lives up to its name, disappearing down a hole every spring.

The intriguing personal collection of a professional demon-chaser.

A clear blue swimming hole with hidden caves, still unexplored.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

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

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

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

The scuba diving training facility was named for the steam that rises from the cave's chimney.

This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

The magic's in the hole!

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

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

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

This incredible collection of vintage pinball machines can be played at 25 cents a pop.

A museum dedicated to the alleged Roswell Incident.

These delicate buggers are some of the rarest fossils that have bubbled up from the Tar Pits.

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

The longest continuous lava tube in the continental U.S. offers 2.5 miles of dark explorations for the adventurous.