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

A cluttered and astounding collection of antiquities and curiosities.

This coffee shop lies hidden beneath a historic church.

Hear the quietest sound from across the dome.

The final resting place to 300 Victorian-era pets hides inside the city park.

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

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

The curios of pharmacist and collector Henry Wellcome.

The anatomical-pathological collection of a man who changed surgery.

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

An unusual round church in London with a Templar past.

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

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

Catacombs turned marketplace.

Rebuilt remains of a temple to Roman god Mithras.

A student driver's nightmare.

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

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

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

This 1920s Dutch barge is now a floating bookstore.

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

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

Eighty million natural history specimens call this gargantuan museum home.

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