All unmarked mute swans on the Thames are owned by the Queen per a tradition that began in the 12th century.

Baltimore's classic clock tower was once topped by a rotating, 20-ton medicine bottle.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

A museum and shop on Bourbon Street located in the French Quarter.

Belly up to the bar in Cowtown, don't forget to buy some boots.

One of America's first dinosaur parks gives a window into Depression-era paleontology.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

A dramatic, 360-degree recreation of Pickett's Charge in the Civil War.

Whitewashed mosque contains the world's largest carpet.

A sign at the end of the Santa Monica Pier marks the traditional end of the legendary American highway.

A preposterously luxurious hotel with gold-plated iPads, Rolls Royce chauffeurs, and a staff that trains by watching "Downton Abbey."

This artificial archipelago was supposed to resemble a map of the world.

Feed it cash, get your very own gold bar.

A century-old hotspot for jazz, frequented by everyone from Charlie Chaplin to Al Capone.

This anonymous businessman sculpted in bronze became an enduring memorial after 9/11, and had been mistaken by rescue workers for a survivor in the rubble.

A dark patch of the ceiling at Grand Central Terminal which was not restored is still stained brown by tobacco.

Unrepaired walls from a 1920 anarchist bomb attack.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

A plaque hangs near the execution place of the Scottish Independence leader famously depicted in "Braveheart."

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

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.