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.

This purpose-built dinosaur museum is shaped like a pterodactyl and holds fossils that were found in its very village.

The UK's oldest theme park slowly slips away.

A museum in England’s Lake District dedicated to the trusty pencil wants you to know the story of their World War II spy pencils.

The bombed out remains of the old church were kept intact next to the new one, as a reminder of the futility of war.

Touching this 18th-century Scottish philosopher’s toe allegedly conjures good fortune.

These picturesque ruins crumble beautifully into the ocean.