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.

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

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

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

This one has sailed five times as far as Sir Francis Drake's famous ship.

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

This modest plaza in Moneygall, Ireland has cashed in on its distant connection to the U.S. president.

Dublin's most modern, visually spectacular bridge is modeled after Ireland's national emblem.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The oldest public library in Ireland.

Limestone caves in the Cambodian countryside, once the site of genocide, now a place of peaceful beauty.

England's largest white horse isn't even white.

One of the oldest and certainly best preserved Cistercian abbeys still in existence.

The first custom-designed building to showcase the works of Dale Chihuly is a wonderland of glass and light.

A luxuriant botanical garden below sea level.

The world's largest piece of copyrighted artwork.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.

This massive tea kettle was once a promotional stunt for the Oriental Teashop.

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

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

Known as one of the most climbed mountains in the world, this barren peak is permanently bald thanks to an anti-wolf fire.

Come for the gun-toting hillbilly madman, stay for the ice-cream loving basketball bears.