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

The largest drain hole in the world.

The longest living non-clonal organisms on Earth.

A meditative space out of a fantasy story.

An abandoned village that doubled as "The Hunger Games"' post-apocalyptic wasteland is up for grabs.

Bizarre lunar-like landscape with thousands of large stone "hoodoos."

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

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

The lush coastal city of Astoria is riddled with forgotten secret sidewalks.

Once thought to be the oldest living tree in the world, Methuselah was germinated before the Egyptian pyramids were built.

A whimsical village of unique treehouses resides in a Washington forest.

The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

A natural gas leak provides a flickering flame beneath a waterfall.

Hundreds of glow-in-the-dark objects light up a museum in a historic zinc mine.

A little piece of the Shire is hidden behind a plant nursery in Port Orchard, Washington.

A 300-yard long natural tunnel runs through a ridge deep in the Appalachian Mountains.

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

This "zoo" is a cross between a junkyard and a sculpture garden, featuring animals you won't see anywhere else.

The haunting, dilapidated remains of a former poorhouse on Staten Island's Greenbelt.

An extraordinary mixture of natural beauty and man-made phenomena.

A sculpture made of 10 Cadillacs as a monument to the "Golden Age" of the American automobile.

An unfortunate geological resemblance to Satan has labeled this Pasadena gorge as a passage to the underworld.

European castle ruins in an American state park are actually the product of death and grief.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.