Wander among the abandoned ruins of this once-powerful medieval town.

This Turkish cave boasts some rather bizarre associations with the King of Mount Olympus.

It's possible to walk inside one of the largest Neolithic tombs in Britain.

The only pub in the world surrounded by an ancient stone circle.

Where the high court feasted, frolicked, and high courtesans put their royal lovers' diamonds to the test.

Nestled within a German forest is an intriguing, growing rock.

Dine on food tied to Viking history and legend at this subterranean Stockholm spot.

A wooden street sign is the last remnant of this 400-year-old alleyway.

This permanent collection of preserved bodies taken from Irish bogs is one of the leading authorities on such morbid mummies.

These otherworldly caverns form Earth's oldest known cave system.

An abandoned tower once used to study the cosmos hides within a thicket of greenery.

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

This weird abode has inspired everything from the "House On Haunted Hil" to a robot hunter's pad.

A naturally mummified 2,000-year-old man.

This bewitching Babylonian goddess haunts a hallway of the British Museum.

There's a labyrinth of medieval chambers hidden deep below a 15th-century pub.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

A labyrinthine underworld of tunnels and caverns hides beneath the city.

This lonely memorial marks the supposedly haunted site of a brutal 19th-century murder.

A 16th-century footpath said to be haunted by a young girl that died trapped within its misshapen old house.

This former maximum-security prison is creepy, sobering, and supposedly haunted.

The strikingly modern structure stands out among the brick buildings speckling the Harvard Business School's campus.

America's greatest forgotten garden and the former stomping grounds of Son of Sam.

It is said the legendary wizard once lived in this sea cave beneath Tintagel Castle.