The most isolated mailbox in America lets desert travelers record their passing.

Travelers leave tea kettles in a remote part of Death Valley as part of a mysterious, decades-old tradition.

The site of an underground detonation of a megaton nuclear bomb in the middle of the Mojave Desert.

A collection of anti-communist sculptures stands watch in the Mojave Desert.

On the outskirts of a desert trading village high on the Andean plain, steel giants have been destroyed by salt winds.

A jaw-dropping "megalibrary" that turns book-browsing into a geometric adventure.

66,000 pieces of art, donated by one of the world's richest men.

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

Big gun installations, built over a massive cemetery, now abandoned & hidden in trees.

Rippling sand dunes frozen in the Arizona rock.

If drivers cross the rumble strip on this stretch of Route 66 at just the right speed it plays "America the Beautiful."

A psychedelic labyrinth on the San Francisco bay.

Trails through lava-carved tube-caves display sparkling bacteria and a rich history.

A serene garden path lined with 36 haiku stamped into clay stones.

In a largely deserted ghost town, a little brick building recalls its history as a gold rush hub and haven for outlaws.

Witnessing the might of this dessert-colored desert waterfall is a rare, powerful treat.