Teeming with illegal goods and services, this towering maze of vice is also a popular tourist accommodation.

This hulking behemoth is actually five interconnected towers built in the 1960s.

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

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

A massive marble foot is tucked away in a small alley near the Pantheon.

Hundreds of lucky felines haunt the ruins where Caesar was murdered.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

Several plaster noses are hidden in plain sight around London's Soho neighborhood.

One part local history, 99 parts gruesome haunted house.

Eighty million natural history specimens call this gargantuan museum home.

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

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

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

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