This overlooked street light once served as a KGB dead letter box.

The 2,000-year-old beam is tucked within the pedestrian entrance to the old London Bridge.

Never actually a tree at all, this spot was the site of London's public hangings for nearly 600 years.

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

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

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Installed at a chaotic intersection, this gave London traffic cops a place to hang their heavy woolen coats.

A friendly pub with a sordid past in cock fighting.

The lab where the scientist made his groundbreaking discoveries is preserved on the basement floor of the Faraday Museum.

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

This luxury shopping lane has been protected by its own tiny police force for over a century.

Charles Babbage's proto-computer, painstakingly brought to life.

The bar where "The Great Train Robbery" was planned was once a nexus of high society and low morals.

The London pub overlooks where the Mayflower was moored before setting sail for the New World.

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

Claiming to be the oldest hat store in the world, this historic haberdashery had a hand (and a head) in the creation of the Bowler.

This beautiful Victorian ironwork masterpiece was built to keep London from smelling like poop.

Remnants of cells from the most notorious London prison may lie in the basement of a rare Victorian Gin Palace.

A naturally mummified 2,000-year-old man.

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

This legendary stone is of unknown origin, and throughout history has been a literal touchstone for British leaders.

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

This small museum in a former church crypt contains artifacts of the Elephant Man, Jack the Ripper and Florence Nightingale.

A collection dedicated to the treatment of disease, held in London's oldest hospital.