Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

There's an exclusive Beefeaters pub hidden in the Tower of London.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

This striking art museum holds an amazing series of curiosity cabinets.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

The granddaddy of English geoglyphs dates back to the late Bronze Age.

To find the "unicorns of the deep" you've got to go downstairs.

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

These pretty kitties killed and ate as many as 135 railway workers.

A lush green oasis in the middle of Chicago.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

Egyptian Revival obelisks still rise over the old mine shafts.

As its grandiose name implies, this wooden dome is unsurpassed in size.

"The Most Boring Road in the State."

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.

Controversial tribute to the heavyweight champion boxer who grew up in Detroit.

A Beaux-Arts triumph rises from decades of decay to become the heart of a new innovation district.

The concrete shell of an industry giant remains as a playground for graffiti artists, auto scrappers, and paintball warriors.