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

There's an exclusive Beefeaters pub hidden in the Tower of London.

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

Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

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

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

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

Despite the name, this ancient piece of crystal may not have been a lens at all.

On October 17, 1814, a 15-ft. wave of beer ran rampant through the streets of London.

Since 1887, this old-school shop has stacked its shelves with extraordinary coffees and teas.

Tucked away in a London Tube station, this 1920s linear clock shows the time across the world all at once.

London's smallest police station is barely the size of a phone booth.

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

A quartet of tiled art pieces adorn the floors of this prestigious art museum.

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.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

The broken skateboards that became a poignant memorial to a murdered skater.

A hidden path at the National Theatre lets you look behind the scenes of the latest productions.

The largest of London's subterranean rivers and once a mad, bad center of London life.

The bridge is a secret gallery of discarded gum that has been transformed into miniature masterpieces.

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

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

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

A sculpture outside London's oldest cathedral honors the Mohegan chief who died while petitioning the king.