A fantastic castle rumored to be the birthplace of King Arthur.

After nearly 60 years, there's still a bear at Paddington Station looking for help.

A network of concealed passageways lies within a busy London Underground station.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

This tangled English forest looks like something right out of a fairytale.

The longest hedge maze in the world.

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

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

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

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

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

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

One part local history, 99 parts gruesome haunted house.

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

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

The sign at the garden gate reads: "These Plants Can Kill."

A tongue-in-cheek arcade where the games are based on everyday life.

This collection of illusory paraphernalia has been culled from the history of London's premier magician's club.

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

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.

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

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."