A bas relief commemorates the "Nuns of the Battlefield" who cared for soldiers on both sides of the conflict.

An abandoned theme park with a strange and tumultuous past.

The remnants of a wooden-hulled fleet built and abandoned in WWI, now home to a thriving ecosystem.

This once-palatial plantation may have been the site where a draft of the Declaration of Independence was written.

Astounding collection of coin-operated games and automata.

A world-class collection of mechanical musical instruments and automata.

Europe's only museum solely dedicated to the history of whaling still has a fully-functioning whaling ship.

Old Danish castle immortalized in Shakespeare's Hamlet.

A walkable map of the world, made from soil and stone by one man.

The lost American era of gunfighters, bandits, Indians and steam trains is recreated in Sweden.

The place to be if you love vintage Swedish cars.

A Gothic-inspired fish market is Gothenburg's best place to find loaves and fishes.

A 200-year-old collection of medical paraphernalia in a historic house.

Walk through Czech history in Prague's largest graveyard.

A tongue-in-cheek arcade where the games are based on everyday life.

Sacked by Vikings, blessed by William the Conqueror, dealt a fatal blow during the French Revolution—these ruins have seen it all.

Remains of a historic fountain that was mysteriously lost in the demolition of a D.C. traffic circle.

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

These steeply terraced ruins are a stop along the Inca Trail to Machu Picchu.

This abandoned Civil War fortress is slowly being swallowed by the waters of Lake Borgne.

10,500 square feet of pinball housed in former dollar store and home to the last playable "Thunderball."

Once defending the city of New Orleans from invasion by sea, this fort faces an uncertain future.

A historic Civil War estate-turned-museum looks back on the Confederate States of America.

Built following the War of 1812, this fort has withstood hurricanes for centuries.