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

The world's largest bicycle shelter can hold more than 12,500 two-wheelers.

A retail shop has preserved the 17th-century food cellar from the old building it now occupies.

An unassuming rod in the Netherlands was once the old standard unit of length for the entire Dutch empire.

A historic observatory now an astronomy museum beautifully situated at the moat of the Middle Age city centre.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

The last of Amsterdam's original sea level markers remaining in place.

This museum inside Amsterdam's largest cemetery explores how people deal with death.

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

The celebrated eyesore created by starry-eyed sweethearts.

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

Stripes of human ashes cover a back lawn in the most sought-after burial grounds in Paris.

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.

An overlooked marble is the only surviving in-place 18th century example of the measurement that changed how we define distance.

The history of radiation is on safe display at the foot of a radiation science laboratory.

A Parisian cemetery where the elite and artistic are interred beneath an eccentric collection of tombs.

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

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.

France's most famous cemetery, with some of its most curious tombs.

The commemorative stone column conceals a secret laboratory.

The London pub overlooks where the Mayflower was moored before setting sail for the New World.

The first tunnel to be dug beneath a river, repurposed as an art and museum space.