Mary Kelly was last seen here before she was murdered by Jack the Ripper.

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

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

After nearly 60 years, there's still a bear at Paddington Station looking for help.

Hear the quietest sound from across the dome.

One part local history, 99 parts gruesome haunted house.

Designed to commemorate the founding of the first settlement in Delaware.

This monument marks the beginning journey of a wounded soldier's leg that ended up almost two states away.

Home of the only civilian casualty at the Battle of Gettysburg.

A dozen U.S. presidents have stayed at the historic resort, which was known as James Buchanan’s “Summer White House” from 1857-1861.

The slate extracted from these Pennsylvania quarries was once hailed as the finest in the world.

Color-coded signs direct drivers on a network of routes designed to avoid Pittsburgh traffic.

The god of wine stares out at passersby on this busy Pittsburgh thoroughfare.

The largest clock face in the United States is twice the size of Big Ben and infinitely more ad-sponsored.

A diorama of the Civil War, fought by cats.

This extraordinary Depression-era expenditure was modeled after a postcard of a Mediterranean hotel.

Hundreds of protractors affixed to surfaces all over the city.

Meet your friends, marry your true love, or tell your enemies to kiss your butt under this historic Pittsburgh timepiece.

It was once the base for a series of domestic terror attacks.

America's Most Wanted's set resides in this tribute to the history of crime and punishment.

The 5.5-mile ring of steel posts around the Capitol Building is one of the largest (and most uniform) of its kind in the world.

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

D.C. once had its own tiny rival to the New York Stock Exchange.

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.