Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.

Painstakingly built dioramas sit unnoticed in a Boston office building.

One of the indelible moments of the American Revolution took place at this location.

This parking garage was the site of what was - at the time - the largest cash robbery in history.

The longest covered bridge in Delaware.

The smallest and oldest covered bridge in Delaware.

The longest-covered bridge in the state of Maryland.

Although built to generate electricity for Marylanders, this dam has become an all-you-can-eat buffet for American bald eagles.

Once America's longest-manned military fort, now an abandoned hulk.

A town trapped in time - 1958 to be exact.

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

A line of blue paint marks the route of the inaugural parade.

Where the U.S. government kept its actual treasure, before Fort Knox.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

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.

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

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

An overlooked memorial honoring the local Washington residents who died in World War I.

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

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

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