19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

A gruesome and mysterious ancient sculpture of a pagan deity from the Roman occupation of Celtic Britain.

This bewitching Babylonian goddess haunts a hallway of the British Museum.

A beautiful Victorian statue shows France's enduring love of the rhinoceros.

The celebrated eyesore created by starry-eyed sweethearts.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

The video game-themed street art first popped up in the French city.

This demon atop the Notre-Dame de Paris looks utterly bored.

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

A counter-culture bookstore like no other hides in plain sight in the streets of Paris.

The narrowest street in Paris.

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

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

This bridge was constructed from the rubble of the infamous Bastille.

An ancient Egyptian obelisk is now used to commemorate fallen Italian soldiers.

Inside this McDonald's you can dine on your Big Mac and fries next to a 2,500-year-old Roman wall.

Terrifically morbid cemetary and site of famous Paracelsus' grave.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

Daily jousts and dancing barrel makers in Munich's mechanical clock.

Known as the "Dodo Manège," this carousel features a herd of animals that have disappeared—or may be gone soon.

This recessed garden protects thousands of mountain plants by creating its own microclimates.

A majestic lion statue guards this Parisian botanical garden, and feeds on an unsettling item.

A fearsome dragon clings to a corner of Munich's city hall.

These 12th-century catacombs carved into a mountainside were a place of mysticism and Christian hermitages.