The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

The granddaddy of all tourist traps, built on ice water, jackalopes, and a giant dinosaur.

Small plaque marks the spot, but the true center is located about half a mile away on a private pig farm.

It's big, it's a ball, and it's made of twine—the world's largest of its kind.

To find the "unicorns of the deep" you've got to go downstairs.

These pretty kitties killed and ate as many as 135 railway workers.

The U.S. Fish Commission’s effort to mass produce carp.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

An overlooked memorial honoring the local Washington residents who died in World War I.

When it comes to handsignals (and colonialism) rock always beats scissors.

Those with a sharp eye can find the hidden image of a German Shepherd on the memorial's Mural Wall.

A museum cafe showcases Native American dishes and indigenous ingredients from across the Western Hemisphere.

The national park was once a plantation estate.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

Home to items never before seen by the public.

This three-dimensional brick mural is the longest of its kind in the United States.