A timeline of London history on the Thames Path, installed in 2014

The ruins of a once-mighty medieval palace are hidden away in otherwise modern London

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 mummified heart of Louis XVII, the lost dauphin of the French Revolution.

A giant silver apple a day keeps the perils of capitalism away.

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

Montmartre's sole surviving windmill became an iconic landmark for 19th-century painters, artists, and bohemians.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

Paris' linguistic guide to the international language of, yes, love.

The first green space constructed on an elevated viaduct.

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

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

The remaining relics of the patroness of Paris lie in a chapel under a striking double spiral staircase.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

The Argonaute submarine was the French navy's pride and joy in the 1950's.

This magical museum celebrates the life and work of a seminal children's book writer (and occasional spy).

Home to the most complete dodo remains known - one head, and one foot.

Ancient Egyptian wigs, South American feather headdresses, a bounty of anthropological artifacts in Oxford.

Looming communist pillar with a Czech twist.

The ruins of a medieval bridge are visible inside a Prague Metro station.

Nine bronze hands protruding from a wall honor the student uprising that led to the fall of Czechoslovakia's Communist government.

Spitfire airplanes with butterfly wings hover over Prague’s skyline.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.

This automated sculpture of two men peeing will spell out text messages with their micturition.