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

The romance of early commercial flight still fills this Art Deco destination.

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

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

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

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

This statue of the "father of television" stands prominently in the United States Capitol.

Rumor has it the uncarved lump behind the three famous suffragists is reserved for the first woman president.

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.

A much-maligned monument to teetotalism.

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

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

There’s a hidden military meme engraved on the World War II Memorial.

The graveyard holding the remains of George Washington's slaves was forgotten for nearly 200 years.

The tomb was guarded by soldiers from both sides of the war, and some left their initials carved in the brick.

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

This unique museum cafeteria showcases the history and regional diversity of African American cuisine.

Beautiful Gothic-inspired lighthouse stands out among the run-of-the-mill striped fare on Bodies Island.

This shifting North Carolina sand dune is an odd little desert surrounded by oceanic forest life.

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

Perhaps the oldest vine in North America, this sprawling plant helps make a sweet wine.

Constructed by the younger brother of George Washington.

This plaque celebrates the sister city relationship between Fredricksburg and Fréjus.

Heron, whitewater rapids, and urban industrialism all add to the beauty of this concrete nature walk.