A stone monument acknowledging Scotland's right to have a separate Parliament from the one in Westminster.

A diorama of the Civil War, fought by cats.

This Civil War monument was designed by an eccentric architect and Gettysburg veteran.

This covered bridge was used by both Union and Confederate troops during the Battle of Gettysburg in 1863.

Ancient human remains unearthed around the iconic monument.

Famously misunderstood wonder of the ancient world

This bewitching Babylonian goddess haunts a hallway of the British Museum.

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

Murals of the wild parties once held on the frozen River Thames.

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

The last remaining example of the boatmen's perches that once dotted the south bank of the Thames.

An incarceration museum on the spot of possibly the oldest prison in England.

These fossilized remains of an ancient saber-toothed cat inspired the mascot of Nashville's NHL team.

A piece of telecommunications history.

Home to a forest of whimsical pygmy Coast live oak.

A massive volcanic plug is now a protected area that hosts a number of bird species.

This cannonball embedded in the side of an Edinburgh house once served a surprisingly pedestrian purpose.

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

Originally meant to hold a statue of King William IV, this support sat empty for years. Today, it hosts a rotating cast of public artwork.

One of America's founding fathers lived in this London lodging between 1757 and 1775.

These wooden pipes were crucial to providing water to Medieval Edinburgh.

Only a few pieces remain of the structure that carried people and goods across the Thames for some 600 years.

The Great Fire of London and the regulation of one-way streets both started in this alley.

A pair of club-wielding guardians stand watch over London's first public clock to feature a minute hand.