These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

The oldest stone house in Paris was built by its most famous alchemist.

Under the right circumstances, this waterfall in Yosemite briefly turns a luminescent fiery orange.

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

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

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

Try not to get slimed in Tribeca.

An enormous, inside-out glass globe built in 1935.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

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

A 140-year-old castle with underground caves hidden in San Francisco.

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

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.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

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

On Japan's Tashirojima Island, cats are king.

An exquisite tunnel of cascading flowers.

Rippling sand dunes frozen in the Arizona rock.

Non-profit time travel mart sells goods you would need for a trip through the fourth dimension.

A peculiar mansion built by the troubled heir to the Winchester Rifle Company fortune.

A psychedelic labyrinth on the San Francisco bay.

A terrific purveyor of natural history objects and curios.