So many migrating birds roost on the bridge, it has a special summer speed limit.

The maritime museum that boasts the largest nautical library in the western hemisphere.

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

Corn-inthian columns with a uniquely American take on neoclassical architecture.

An ear-piercing buzzer calls lawmakers to a vote with a series of long and short rings to form coded messages.

The innocent intentions of this monument are somewhat lost in the sculpture's muscled imagery.

An atomic bomb-proof strongbox protects the U.S. Constitution from terrorists and thieves.

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

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

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.

A derelict bit of infrastructure from the canal that once ran through D.C. is landlocked in the heart of the city.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

The National Park Service’s best-kept secret with views that rival any in D.C.

The actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

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

This shale formation along the Appalachian Trail once inspired the third president of the United States.

Built in the 1850s, this church was of the first five churches constructed in Harper's Ferry.

The last holdout of a pre-Civil War rebel who took the matter of slavery into his own hands.

Hear, smell, see, taste, and touch history at this immersive Civil War hospital.

This Civil War monument was designed by an eccentric architect and Gettysburg veteran.

The highest point in New Jersey is marked by a massive, if simply named, obelisk.