The grand marble structure next to the White House is Andrew Carnegie's temple to Pan-American diplomacy.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

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 "lovely red Vega" of the legendary record-settling pilot.

Obscure Freemasons still live in D.C.’s largest private residence.

A celebrity from the late Cretaceous period.

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

The most decorated dog of World War I is preserved in the Smithsonian.

The walls of the iconic dome are hollow and have a secret stairway.

This distinctive Crescent City tradition dates back to the days of horse-drawn carriages.

Once the site of a Native American harvest festival, this humble clearing later played an invaluable role in the birth of jazz.

The oldest family-run restaurant in the United States is a living museum of New Orleans dining history.

For 150 years one family has been producing the iconic hot sauce on a bayou island made of salt.

This "second" cemetery represents New Orleans' attempt to keep cholera at bay.

By day this New Orleans square is for pedestrians, but by night it is a kingdom of kittens.

This historic "City of the Dead" lies prominently in the center of New Orleans' famous Garden District.

This historic sunny-yellow building has an unfortunate connection to the sinking of the Titanic.

The lesser-known lost colony of Roanoke was a safe haven for formerly enslaved people during the Civil War.

The Cadillac Ranch for monster truck aficionados.

Proto-CIA agents trained with grenades in the sand traps and fired machine guns from the fairways.

This massive swimming pool is the high tech home to the human-powered submarine races.

Home of the physician who set the leg of John Wilkes Booth after the Lincoln assassination.