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

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

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

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.

A nostalgic bibliographic gem.

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

The winding route passes through an enclosed alleyway, two tunnels, and leads to the White House basement.

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

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

The oldest continuously operating fish market in the United States.

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

These bronze sculptures sow whimsy by hamming it up on a pedestrian mall.

These mythological giants take time out of their busy day guarding a Victorian market to let you know what time it is.

The once-dying town of Sheffield, Tasmania has reinvented itself as a village of painted wonders.

An incredible garden taking over the interior of a massive sinkhole.

An easy to overlook storefront hides some of the most authentic and regionally diverse Chinese food in New York.

The very center of Paris is surrounded by a bevy of strange good luck rituals.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

This historic train station has been converted to a locomotive themed hotel.

This pun was simply waiting to come to life, and one defense contractor made it so.

Once decrepit and slated for demolition, now one of the longest pedestrian bridges in the world.