A superbly preserved example of Georgian residential architecture that was once home to one of the founders of Alexandria, Virginia.

The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

The first American department store, and home to the largest operating musical instrument in the world.

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

The longest-covered bridge in the state of Maryland.

The park is home to the United States's only still-operating Dutch windmill.

This beloved Baltimore spot features caged dolls, a giant Pez collection, and many, many mannequins.

Crammed into a Baltimore row house is an oddities shop that sells everything from skulls to dead insects.

Wedged between two sets of row houses is an awkwardly located family graveyard.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

A blank headstone topped with a pile of pennies marks the final resting place of the infamous assassin.

The man who first patented the Ouija board rests in peace beneath a headstone that playfully reflects that achievement.

The trials and tribulations of marking Poe's grave.

The face of a woman pushes its way through the earth.

The world’s largest truck stop includes a barber shop, chiropractor, and a huge museum with antique trucks.

This monument traces the segregation line that inspired the first rural branch of the NAACP.

Through the decades, Black music stars have performed at this historic hub for music and the arts.

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

On the Fourth of July this area will transform into a Pompeii-like storm of falling embers and ash.

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

Seemingly unremarkable items like empty sushi trays, chef hats, and freshness stickers are being preserved so future generations can look back on this beloved cultural import.

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

The 28,000-year-old specimen is remarkably intact.

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