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

The installation’s official name, “You Who Are Getting Obliterated in the Dancing Swarm of Fireflies,” says it all.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

This secluded aqua waterfall in the Grand Canyon is the perfect swimming hole, and the Havasupai tribe's fiercely protected natural wonder.

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

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

Dramatic river bend surrounds a natural red-rocked pedestal.

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

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

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

One of the last of the great 1920s movie palaces is a Floridian Greco-Spanish-Persian dreamscape.

This ancient cave is home to a museum, bar, and is filled with fluorescent minerals.

A hidden barn-sized rendition of Grant Wood's most famous, and most parodied, painting.