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."

The hidden offices underneath Memorial Bridge have been locked up since 1976.

This lovely picnic spot featuring thunderous jet landings is an aircraft spotter’s dream.

At 207 feet, one of the world's longest continuous escalators.

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

This historic boathouse was constructed using salvaged lumber from burned barns.

The site of the climactic scene from the classic horror film is now a historic landmark.

The little-known, 300-year history of the area includes former lives as a bustling tobacco port, parking lot, and industrial dump.

The oldest building in the District of Columbia was preserved because of a mistaken connection to George Washington.

This robust fence in front of a historic Georgetown home is likely made from hundreds of recycled Revolutionary War firearms.

Mausoleum and Holy Seat of Antiochus I of Commagene.