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

The "lovely red Vega" of the legendary record-settling pilot.

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

Perhaps the most scandalous statue of America's first president.

This lovely pocket park is one of the most under appreciated in D.C.

The most accurate timepiece in the world.

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

D.C.'s first central library was born out of a chance encounter with the philanthropist whose name it bears.

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

Home to a vast and influential collection of Shakespeareana.

The house where John Wilkes Booth conspired with his co-conspirators.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

The oldest continuously operating fish market in the United States.

A rotating cast of guys and dolls in front of a Washington, D.C. building.

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

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

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

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

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.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

A promising candidate for the lost rock laid by George Washington was unearthed, but the hunt is still on.