Final resting place of Typhoid Mary.

Ruins of an American Civil War iron forge still survive today.

This stunning home looks like it belongs in medieval Europe, not North Carolina.

The rustic think-space of famed naturalist John Burroughs stands exactly as he left it.

Over fifty whirling pools left by the glacial age.

This wall on a street corner in Lower Manhattan has been a blank canvas for a rotation of renowned artists since the 1980s.

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

It was once the base for a series of domestic terror attacks.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

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

This unique museum cafeteria showcases the history and regional diversity of African American cuisine.

This unassuming passageway played a key role in one of the most important events in U.S. history.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

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

Before Nixon, "watergate" meant canals.

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

A replica of the famous memorial statue at the Normandy American Cemetery hides in an office building in downtown D.C.

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

A brass plaque dedicated to a convicted cannibal hangs in the National Press Club, and that's not even the craziest part of the story.

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

Behind an abandoned storefront is an example of pioneering 1930s gas station architecture.

An amazing example of early-20th-century architecture, this church features marble transported from Utah.

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

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