The site of one of the largest prison escapes of World War II.

This 13th century Gothic brick castle is the largest in the world by surface area.

One of the world's largest collections of medieval religious art.

A memorial to the beloved brown bear that served in the Polish army during World War II.

Few of the many visitors to this resort town know of its hidden Maya ruins.

A historic bridge no one is allowed to cross.

An anonymous art project beneath Longfellow Bridge where hundreds of trophies line the steel support beams.

Utopia and nostalgia mingle at the site of Bronson Alcott's ill-fated agrarian commune.

Take a step inside the picturesque studio of America’s most renowned sculptor.

This tower commemorates the spot where George Washington hoisted the Grand Union flag.

The final resting place of a free Black soldier who played a pivotal role in the Battle of Bunker Hill.

The largest collection of historic military firearms in the United States.

She become one of the first women to serve in the United States military by secretly dressing like a man.

Around 160 years ago, this spot marked the location of a wharf along the shores of the Charles River.

This old mill and former police station now present a world-class collection of Orthodox iconography.

Mass Grave of 48 colonists killed in a raid by Native Americans and the French in 1704.

Burial ground for revolutionary veterans attracts tall tales, ghost hunters, not enough historians and preservationists.

This hidden labyrinth offers walkers some brief peace of mind.

This dam in the woods, built by Henry Ford with only manpower and oxen, holds no water and serves no purpose.

Ornate and macabre headstone in one of the country's oldest cemeteries.

The oldest surviving wood-frame building in North America is still in the family.

This Cape Cod museum exhibits what it claims is the only authenticated pirate treasure in the world.

It was an experiment to prove that glacial boulders and rocks can be used in constructions and dwelling.

Locals purchased this abandoned quarry in order to make sure it continues to be overgrown.