Part of a WWII submarine is lurking outside the Washington Navy Yard parking lot.

The U.S. Navy’s preposterously detailed mini battleship took 77,000 hours to complete.

This statue honors the author's groundbreaking family story.

Rediscovered after a century, the father of the American Navy was reinterred in something dredged up from Davy Jones' Locker.

The oldest military monument in the United States.

The highest point in Washington state is a volcano covered in glaciers.

The oldest surviving presidential residence in the United States.

America's smallest national park site is the former residence of exiled Polish national hero Thaddeus Kosciuszko.

Current docking place of the SS United States, the fastest transatlantic ocean liner.

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

This elaborate towering structure was once famed for its revolutionary height.

In the early 1800s, surgery was also a show.

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

This meticulously extracted nervous system allegedly came from a 19th-century custodian who donated her body to science.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

The world's first aircraft factory has been hiding inside an automobile plant for almost 80 years.

This graveyard contains markers and monuments dedicated to some of the darkest chapters in Washington's history.

Parking garage where Bob Woodward met Watergate source "Deep Throat."

A gift from Scotland to the United States in memory of the 270 lives lost when Pan Am Flight 103 exploded over Lockerbie due to a terrorist bombing.

Rusting away on the edge of New Jersey are the remains of a Cold War missile launch site.

The unluckiest U-boat in the entire German fleet is now on display in a Chicago museum.

The site of the gruesome massacre—and maybe cannibalism—of five men, a tragedy that made Alferd Packer infamous.

Inside houses a vast collection of military aircraft and missiles spanning the ages.

You can walk through the first Boeing Air Force One, which famously carried JFK's casket from Dallas back to D.C.