The world's second-longest burning light bulb.

The fountain marks the area where hundreds of accused witches were burned at the stake.

Northern Ireland's Brobdingnagian stepping stones.

The atmospheric road was never meant to be so creepy.

Famously misunderstood wonder of the ancient world

The most iconic structure in Scotland has been home to bishops, colonels, and Sean Connery characters.

The world's largest collection of witchcraft regalia.

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

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

This South London cemetery holds the remains of more than 15,000 people.

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

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

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

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

A museum dedicated to the history of psychiatric treatment featuring a gallery of art made by patients.

A kaleidoscopic warehouse-maze of handmade neon signs.

These fantastically named natural pools look like something out of a Scottish myth.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

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

This former asylum for Black Americans is haunted by its history of violence and racism.

Once known as the Illinois Asylum for the Incurable Insane.

This small museum displays a collection of outsider art and scale models of past "treatments" for mental illness.

This former abandoned hospital, a complex of stunning 19th century buildings, once housed 2,000 psychiatric patients.

A subterranean world of tunnels links several buildings of this rare 19th-century asylum.