A memorial for public executions that dates back to the 14th century.

A discarded movie prop that was the original monolith for "2001: A Space Odyssey."

This ancient Egyptian obelisk still bears the wounds of World War I.

The Art Deco artwork depicts gilded carriers of deadly illnesses.

A measuring mishap led to these artificial stone ladies losing their stomachs.

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

London’s first road overpass is so old that it was originally built for horse-drawn carriages.

This sprawling, Brutalist estate feels like a city within a city.

A tribute to all the green-thumbed workers who tend London’s public parks and gardens.

One of London’s rare Tudor-era buildings is a fate-defying gatehouse for a church.

A famous burial ground with a history both grim and literary.

The middle finger of modernity.

The largest and most famous wax anatomical collection anywhere in the world.

The mysterious “claw marks” said to be left by the Devil on Pisa’s famous cathedral.

A museum on the history of Paris, including a set of Napoleon's toiletries, Proust's room, and relics of the Revolution.

Remains of Roman amphitheater hidden in a sleepy quarter of Paris.

The remains of the medieval wall that once surrounded Paris with ties to the construction of the Louvre.

Offal and flawless onion soup are on the menu at this restaurant that once catered to the workers of Les Halles.

Two awe-inspiring globes from the reign of the Sun King hang from the ceiling of France's national library.

This 400-year-old tree is actually an immigrant from North America.

Notorious artist squat renovated into legal studios.

A glamorous hotel that once accommodated French resistance fighters and concentration camp survivors.

A popular shrine where the Blessed Virgin allegedly appeared in 1830, displaying a holy armchair and two incorruptible remains of Lady Saints.

In the best of all possible worlds, everyone will get a chance to see this statue in which Voltaire's heart is interred.