An entire city block built completely out of petrified wood.

This replica stave church looks like a piece of Norway was simply plopped down in South Dakota.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

These former Cold War launch sites have been preserved for tourists to see where the button might have been pushed.

The remnants of an early American attempt at missile defense.

The world's largest Holstein cow.

Part of a secret 1970s nuclear defense program is now open to the public.

This sky-high radio mast is formerly the tallest man-made structure in the world.

New Plymouth, Idaho is the only U-shaped town in the United States.

Sweet Willy, at 30 feet tall, is the world's biggest beagle.

Rippling sand dunes frozen in the Arizona rock.