A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

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

Repository for more than 22 million pickled specimens.

Mysteriously stacked storefront paths give this medieval British town an iconic style like none other.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

Eighty million natural history specimens call this gargantuan museum home.

The site of London's first coffee house has been serving refreshments of one kind or another for 360 years.

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

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

Surreal riveted sea forts once protected the Kent shores from German attack.

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

A special shop catering to the needs of things that go bump in the night, and also helps kids become writers.

The quaint little store that is said to have inspired a famous Dickens novel was only given its name after the book was released.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

Rebuilt remains of a temple to Roman god Mithras.

The gloomy ruins that inspired Bram Stoker to bring Dracula to life.

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

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

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

The longest hedge maze in the world.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

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

Famously misunderstood wonder of the ancient world