This vast masterpiece of Moroccan architecture spreads across 20 acres.

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

The oldest known university in the world is in Fez, Morocco.

Crumbling necropolis set high above Fez.

Thousands of narrow alleyways in an ancient medieval city make up what's believed to be the world's largest car-free urban zone.

The courtyard of this small Marinid madrasa is a dazzling example of intricate Islamic architecture.

Traditional 11th-century outdoor tannery.

The other side is actually green.

This influential Renaissance-era library was once the haunt of kings and monks.

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

Hidden behind a wall, Spanish nuns distribute their signature sweets on a revolving tray.

The Devil’s own choice when he needs a drink in Brussels.

This magnificent museum claims to house the cranium of a disciple and the skull of a pope.

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

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

Daily jousts and dancing barrel makers in Munich's mechanical clock.

A fearsome dragon clings to a corner of Munich's city hall.

The patron saint of spinsters grasps a container of dried blood.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

William Blake claimed to have painted this gothic masterpiece after encountering this nightmarish being in a vision.

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

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