Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

Ice cream stand, snack bar, and time capsule of milk conveyance.

This landmark cemetery in Boston was created more than 300 years ago.

Narrowest house in Boston.

The massive machine creates cracking displays of indoor lightning.

The site of Paul Revere's historic two lantern warning.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

The site of one of the strangest disasters in history—a wave of deadly molasses traveling at 35 mph.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

One of the oldest used bookstores in the U.S. has been selling antiquarian treasures since 1825.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

An enormous, inside-out glass globe built in 1935.

This unassuming alcove in London’s famous Tower Bridge once served to capture, store, and display dead bodies from the River Thames.

The wooden telephone box hidden away in London's Piccadilly was the original prototype of the iconic kiosk.

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

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

This long-hidden space above Westminster Abbey now displays the battle gear of the legendary King Henry V.

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

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

A naturally mummified 2,000-year-old man.

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

This massive collection of British military artifacts includes the heartbreaking personal letters of the men in the trenches of WWI.

Scattered throughout London are ancient remnants of the city's former bounding wall.