The library houses an incredible collection of some of the world's most impressive books and manuscripts.

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

The last four extravagant street signs of London's historic banking street.

The fierce beast perches atop a pedestal marking where the historic City of London gates once stood.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

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

A statue marks the exact spot where The Boy Who Never Grows Up made his first literary appearance.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

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

The Metropolitan Police refurbished the blue box (perhaps not coincidentally) the same year "Doctor Who" returned to TV screens.

The television series' iconic giant foot was borrowed from this classical painting.

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

A cluttered and astounding collection of antiquities and curiosities.

One part local history, 99 parts gruesome haunted house.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

Once called the "Polish Gold Coast" it is an icon of the neighborhood that bears its same name.

This alley in downtown Chicago held the bodies of over 600 people after the fateful Iroquois Theatre fire.

This historic hotel invented the chocolate brownie.

A gothic church spire sits atop this skyscraper, the tallest church in the world.

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

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A massive marble foot is tucked away in a small alley near the Pantheon.

In Florence's great Duomo, a 26 foot fresco honors a mercenary famous for attacking Florence.

This ancient market is often referred to as the oldest shopping mall in the world.