A museum dedicated to the alleged Roswell Incident.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

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

Dedicated to the history of the 1,000 nuclear missiles that once covered the Great Plains.

A striking sculpture built to honor the women of the Lakota and Dakota Nations.

A cemetery housing wild west legends in South Dakota.

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

A true roadside icon standing on the same plains that the herds once roamed.

It was once the base for a series of domestic terror attacks.

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

One of the most influential presidents in U.S. history wanted only this plain, elegant monument as his lasting memorial.

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

Look closely and you’ll notice that the color changes a third of the way up the tower.

There's an old indoor swimming pool hidden directly underneath the White House Press Briefing Room.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

Washington's iconic carousel has a nice piece of Civil Rights history.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

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

Fittingly, America's museum of architecture is itself a magnificently designed old building.

This playground sculpture of an icon from the past is dedicated to the children of the future.

The highest point in Washington state is a volcano covered in glaciers.

This Seattle store is packed with all sorts of curious creatures and creations.

A wall of chewing gum moonlights as collective art.

A 100-year-old purveyor of curiosities, curios, and kitsch featuring mummies, shrunken heads, and a Fiji Mermaid.