A museum dedicated to linguistics, from how babies learn to talk to endangered and extinct languages.

A giant Troll lurks under one of Seattle's oldest bridges.

Makers and sellers of the original and finest York Ghosts.

This memorial to World War II's fallen airmen shows us the movements of the stars that once guided them.

Semaphore saints, a golden dragon's head, and a stone carved with religious warnings all call this cathedral home.

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

Berlin's old airport.

For decades, a bottle factory dumped their waste into these waters—now it's considered the best sea glass beach in England.

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

This seaside Italian village doesn't just look Escher-esque, it actually inspired the mind-bending artist.

A domino effect created with Britain’s iconic telephone boxes.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

A 19th-century subterranean reservoir repurposed as a contemporary art cave.

The longest canal aqueduct in England was built without a plan to get water past the moving boats.

This unique sculpture is often overlooked by pedestrians.

Indents in the pavement are all that remain from a grisly death machine in Paris.

The underground sanctuary of a mysterious ancient cult.

The yawning maw of this pagan visage is said to bite off the hands of liars.

France's most famous cemetery, with some of its most curious tombs.

A monument to the thrice mayor of London who according to lore made his fortune by selling his rat-chasing cat.

Original cabaret handbills, posters, and feline artwork are a purrfect highlight of the Museum of Montmartre.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

A floating cat sanctuary on an Amsterdam canal.

This bronze statue was erected to honor a small Scottish town's beloved stray cat.