A beautiful but toxic fountain of mercury.

Finland's oldest astronomical observatory once played a crucial role in seafaring and timekeeping.

A collection of collections ranging from dentistry to minerals.

This set of concrete chambers resonates according to different notes of octaves.

The door to the museum holds a unique artifact from the Finnish Civil War.

This historic electric train has operated with regularity since the early 1900s.

This historic club for wayward boys has shaped some of the biggest names in music almost as much as they have shaped it.

Catalonia Tradition: Beating the hollow Christmas log until it defecates in your fireplace.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

The former home of Dutch anthropologist Bert Flint now houses a collection of Berber art and artifacts.

A famous pilgrimage site that remains hidden in the midst of a city.

This century-old grotesque has a mysterious history and may not actually be a rabbit.

The Brutalist building harbors an unusual inverted dome that swoops down over its central sacred room.

Housing the famous Norwegian ice-defying 19th century polar exploration ship.

Across the Pacific in a raft, a museum dedicated to Thor Heyerdahl's now legendary expedition.

Home to three historic ships from the age of Vikings.

This abandoned mining village was predicted to resist decay longer than any other modern human settlement.

The world's northernmost brewery uses water from a 2,000-year-old glacier to create its beer.

An incredibly well-preserved piece of ninth-century Viking poop.

This former “ante-chamber to the guillotine” has been refurbished to illustrate the brutal history of French justice.

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

A haunting collection of the vanished and disappearing natural world.

A museum on the history of Paris, including a set of Napoleon's toiletries, Proust's room, and relics of the Revolution.

The very center of Paris is surrounded by a bevy of strange good luck rituals.