A beautiful Gilded Age hotel in the White Mountains with surprising diplomatic history.

All that remains of the once-booming chain is a single orange-roofed restaurant.

A hamlet full of permanent Christmas spirit holds one of the earliest theme parks in the United States.

This historic fort spans more the 300 years.

This monument marks the beginning journey of a wounded soldier's leg that ended up almost two states away.

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

This large stone residence served as a field hospital during the Battle of Gettysburg between stints as a tavern.

This is the spot where the bloodiest battle in the American Civil War may have started.

Disks are rolled out onto the south lawn to absorb the impact of Marine One's wheels like giant coffee coasters.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

This simple stone memorial remembers a secret, Geneva Convention-defying interrogation base from WWII.

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.

One of the largest artillery pieces in the world sits in a Washington D.C. parking lot.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

While most wind tunnels test scale models, the "Cave of Winds" was large enough for actual airplanes.

Washington's iconic carousel has a nice piece of Civil Rights history.

The story behind this beloved toy—named for Theodore Roosevelt and owned by his grandson—is more complicated than you might guess.

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

These expertly crafted, scientifically accurate glass sea creatures were once an international phenomenon.

All that remains of one of the Civil War's more deadly POW camps is a simple flagstone.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

An interesting look into 18th-century American history.