Catacombs turned marketplace.

Rebuilt remains of a temple to Roman god Mithras.

The world's first underground farm is in a World War II bomb shelter beneath the streets of London.

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

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

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

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

Eighty million natural history specimens call this gargantuan museum home.

Hidden beneath the streets of London is a secret subway that only carried mail.

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

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

An easily overlooked stretch of ornate window fronts and gaslight lamps that could be right from the pages of Dickens.

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

The “Grand Canyon of Maine” is a three-mile gorge full of striking geological features.

This coffee shop lies hidden beneath a historic church.

This pub was 238 years old when it decided to revamp its image: It started serving Thai food.

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

Revel in the Victorian splendor of the world's oldest eating establishment inside a museum.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

A 300-year-old tea shop that brought tea to the English people, not to mention the Queen herself.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

A kaleidoscopic warehouse-maze of handmade neon signs.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.