An arsenic-filled pool in the Grand Canyon takes on the appearance of a giant, overflowing pumpkin.

The gloomy ruins that inspired Bram Stoker to bring Dracula to life.

Stalactites and stalagmites in a beautifully lit cave.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

Walk 2,300 feet above the ground on the "Troll's Tongue."

The most alien-looking place on Earth.

These fantastically named natural pools look like something out of a Scottish myth.

Heron, whitewater rapids, and urban industrialism all add to the beauty of this concrete nature walk.

The remains of an idyllic small town built for the film 'Big Fish' still stand around a rundown main street.

More than five miles of underground passageways.

Better known as the "Body Farm," this unique research facility has been studying how human bodies break down since the 1980s.

The abandoned Japanese amusement park once loomed as a dystopian Disneyland.

What was once the largest NFL stadium.

A natural wonder in south Denmark.

A Hawaiian stairway to heaven—that you can't climb.

An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

Stroll through a wonderland of stupendous moss-covered trees.

A gargantuan crystal kingdom.

Keshwa chaca, among the last handwoven Incan bridges, crosses Apurimac Canyon in Peru.

Hollowed out cedar log tubs set in an ancient towering forest.

Wondrous sandstone hoodoos where Native Americans collected clay for pottery, 9,000 years ago.

Crystal clear lake with a shoreline of travertine located in a Colorado canyon.

A spectacular cave and a beguiling lake.