Here, at the "world's longest art gallery," you'll find forty miles of ancient petroglyphs and pictographs.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

Enormous lake at the bottom of a unique cave system.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

The United States Capitol's former columns still stand.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

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

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

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

It should come as no surprise that the best view of the Hollywood sign is from Batman's lair.

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

A bizarre house filled with an astounding array of collections.

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.

Remants of foundations, streets, and streetcar tracks inhabit the cliffs where a landslide occurred in 1929.

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

Dramatic river bend surrounds a natural red-rocked pedestal.

These old stone ruins in the Oregon wilderness were once bathrooms and are steeped in legends of murder.

An emerald-green grotto just a short trip from Austin.

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

On the Oregon coast there is a natural hole that seems to be draining the sea.