Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

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

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

A six-ton wedding present for the King of the Scots.

This series of Scottish caves has no clear purpose other than baffling historians.

The final resting place of soldiers' loyal canine companions.

A succession of eerily contemplative iron figures lead from a Scottish museum to the sea.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

The tomb of one of Scotland's bloody historic villains is a magnet for bumbling desecrators.

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

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

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

Protecting the dead from opportunistic body snatchers.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

Venice's "Island of the Mad."

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

Go inside to really appreciate this 500-year-old technological masterpiece.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

Charles Dickens was not a fan of the ghastly wall dressings in this 6th century church.

A mysterious chasm in the heart of the ancient Roman Forum, the Lacus Curtius was once believed to be a gateway to hell.

Among the ostentatious rococo ornamentation of this church, an image of death cuts the life-thread.

Housed in an old church, this hunting museum holds a collection of mythical bird-rabbit creatures.

The footprint of a frustrated devil in Munich's Cathedral.