The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

The "Key of Keys" for Washington, D.C. and the apocryphal landing place for the military campaign that started George Washington's career is now at the bottom of a well.

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

Decades before the scandal, this staircase on the river was a literal "water gate."

A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

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

This cannon dating to 1755 has stood guard at this suburban intersection since 1915.

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

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

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

A gift from Scotland to the United States in memory of the 270 lives lost when Pan Am Flight 103 exploded over Lockerbie due to a terrorist bombing.

In what is rumored to be an intentional act of spite, this memorial almost completely obscures the nearby grave of a senior officer.

A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

Was there a small "backpack nuke" hidden in the attic? JFK apparently thought so.

This 18-foot-tall public art installation is another of sculptor Thomas Dambo's trolls.

Overlooking Puget Sound sits a garden with a Buddhist prayer wheel and an elaborate labyrinth.

The small town of Poulsbo in Washington state is the next best thing to the Kingdom of Norway.

Sweet or salty, super hot or mixed into beer, this is the holy land for all things licorice.

A once celebrated industrial wonder now lurks in a quiet corner of Flathead Lake.

The rodent-shaped sidewalk imprint that earned worldwide media attention.

A goddess-topped water fountain in Chicago was created thanks to the dreams of a thirsty newsboy.

A small collection of iguana-infested ruins hides amid Cancún's bustling hotel zone.

The Cadillac Ranch for monster truck aficionados.