This massive library holds what was once the largest book collection in the world.

One of the oldest medical collections in Europe focusing on rare surgical instruments.

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

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

Notorious artist squat renovated into legal studios.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Most prolific publishing house in the 1600s open to the public.

A maze of crosses marks the jumbled divide between the Netherlands and Belgium.

Christ's blood allegedly preserved in a Belgian town.

A little sculpture with a large wardrobe.

Cozy basement bar sports an inventory of over 2,000 beers.

Climb inside an iron crystal magnified 165 billion times its normal size.

There are plenty of wonderful panoramic vistas in Edinburgh, but not many are hidden smack in the middle of the Old Town.

The most loyal of little dogs, or a Victorian era publicity stunt?

Protecting the dead from opportunistic body snatchers.

A book bound in the skin of an infamous criminal, along with countless other specimens.

Tiny effigies of the victims of Edinburgh's famous Anatomy Murders.

A theatre built to house the rowdy Oxford graduation ceremonies became the stage for a debate about God's existence.

J.R.R Tolkien, C.S. Lewis, and other "Inklings" met at the Oxford pub to discuss the now legendary fantasy stories they were writing.

One of Europe's oldest libraries.

Public access to clean drinking water was an instant hit among the masses.

Giant, friendly pelicans in Central London, the most unlikely of places.

Eighty million natural history specimens call this gargantuan museum home.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.