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

This modest marker near Notre Dame identifies the very center of Paris.

This former “ante-chamber to the guillotine” has been refurbished to illustrate the brutal history of French justice.

A 400-year-old church covered floor to ceiling in ex-voto offerings from the faithful.

This small, ingenious cannon once helped regulate Parisian life.

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

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

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

This bewitching Babylonian goddess haunts a hallway of the British Museum.

This luxury shopping lane has been protected by its own tiny police force for over a century.

This ancient spring in central London was featured in a Peter Pan story.

This once-controversial and slightly confusing statue of Achilles was built out of captured cannons.

It holds a fabulously designed tribute to astronomer Edmond Halley.

This long-hidden space above Westminster Abbey now displays the battle gear of the legendary King Henry V.

The niches over the western entrance of Westminster Abbey honor individuals from the 20th century who gave their lives for their Christian beliefs.

At almost 1,000 years old, this is the oldest known door in all of Britain.

The "beautiful" equation predicting the movement of all electromagnetic particles is engraved in front of Newton's tomb.

This statue includes the molehill that toppled a king.

The London statue that imitates passersby.

This hand-painted advertisement is a literal sign of encouragement, however unintentional.

An architectural oddity hides in plain sight on this iconic London bridge.

There's an exclusive Beefeaters pub hidden in the Tower of London.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

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