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

Remnants of a Victorian garden feature sitting in public woodland.

Catacombs turned marketplace.

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

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

One part local history, 99 parts gruesome haunted house.

A student driver's nightmare.

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

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

Banksy gives themself artistic license with this piece of London street art.

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

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

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.

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

A kaleidoscopic warehouse-maze of handmade neon signs.

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

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

This 5,300-year-old tomb with mysterious carvings crowns an Irish mountain.

On the Irish coast, 18 members of the Howard family are eternally resting in an Egyptian pyramid.

This Bronze Age tomb is the centerpiece of a clearing within a beautiful Irish forest.

Ireland's only German military cemetery holds the remains of a spy who was moved there under the cover of darkness.

This ancient Irish tower could easily have stood in for Rapunzel's prison.