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

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

The famous winding walk at Chartres is surrounded in mystery and myth.

A cave dwelling that was started by the Celts, expanded by monks, and finished by knights.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

Site of a classic 19th-century physics experiment to prove the earth is rotating.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

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

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

The walls and streets of the ancient city are peppered with penises.

Ancient snack bar of the Roman Empire re-opened.

Erotic art covers the walls of the largest ancient pleasure palace.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

The somber sculptures commemorating Irish Famine on the river Liffey in Dublin.

A strange egg in a mucky bog of western Ireland marks the spot of an aviation milestone.

Single runway interrupted by a busy road that cuts across its middle.

This charming old building's loose connection with the Scottish Reformer is what saved it from demolition after it split apart.

An exercise in radical design and social living that became the epicenter of Soviet spy networks in London.

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

This British museum hopes to take the taboo out of poo.

The fantastic charm of England's oldest botanical garden has made it a place of writerly inspiration for centuries.

Home to Alan Turing, the cracking of the Enigma code, and Captain Ridley's shooting party.

This beautiful deer park was built so King Charles I and his court could go hunting while escaping a deadly plague outbreak.