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

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

A historic ruin just 20 feet away from a busy highway onramp.

A celebrity from the late Cretaceous period.

The oldest continuously operating fish market in the United States.

A winding district gerrymandered into the shape of a mantis.

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

A priceless collection of the Nation's cryptologic history.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

Members of Congress have traveled between the buildings on Capitol Hill for a century hidden from tourists, press, and storm clouds.

A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

The country's oldest continually-operated mini golf course lies hidden in plain sight, eclipsed by one of D.C.'s most popular tourist attractions.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

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

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

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

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

The preamble to the U.S. Constitution written entirely from vanity license plates hangs in the Smithsonian museum.

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

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