Beyond being incredibly fun, not much can be said about the Hole with certitude.

A place where the laws of nature seem to have gone completely berserk... but of course haven't.

The "mysteries" of this quintessential roadside oddity were almost destroyed by neglect but were saved by fans of kitschy wonder.

A self-built castle made by a mysterious man.

The ghostly remains of an accidental sea.

Eighteen miniature death-scene dioramas.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

A roaring, awe-inspiring double cascade of icy water flows through woodland Oregon like something out of a Tolkien novel.

Collapsing castle on the Hudson river was once the storage site of military surplus business.

An Australian lake whose pink hue defies scientific explanation.

High on a hill overlooking Los Angeles lives a world famous, high power conical Tesla Coil.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

The abandoned zoo enclosures offer a perfect place to experience the other side of the bars.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

An old vending machine serves up unpredictable beverages from its seemingly magical insides.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

A crumbling hospital from the 1850s on Roosevelt Island.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

The rocks in this arid basin leave trails of movement behind them.

Medicinal spa created with the discharge from a geothermal energy plant.

A collision of human error and natural geothermal pressure created this rainbow-colored geologic wonder.

Most-visited and most-photographed slot canyon in the American Southwest.

An artsy hidden staircase leads to breathtaking views of San Francisco.