This naturally heated mountainous creek has created a group of neon blue pools of potentially deadly boiling water.

This odd Chilean waterfall-cano hotel must be entered via a rope bridge.

One of the largest, oldest, darkest, quietest motel rooms in the world.

America's only nuclear missile silo open to the public.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

Accessible only at low tide, the deserted island is dotted with World War II ruins.

A miraculous natural phenomenon known as "the spring that breathes."

Treehouse motel and treehouse-building school.

This expansive bridge in the Canadian wilderness was originally just built for friends.

Sandstone rock formations that look like they belong on the cover of a progressive rock album.

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

400-year-old garden, restored to beauty.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

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

The longest living non-clonal organisms on Earth.

A strange rock with a sinister reputation lurks within the crimson waters of this Scottish glen.

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

This free, take-a-book shop seems like a trick but isn't.

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

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

An Oxford museum where visitors can have tea with the Mad Hatter and climb through the wardrobe to a fantasy land.

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

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

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