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

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

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

This bridge was constructed from the rubble of the infamous Bastille.

Massive puppet-automaton machines created by French artist collective Machines de l’Ile.

A young Gustave Eiffel assisted in the construction of this skinny metal observation tower.

The world's largest reflecting pool is just two centimeters deep.

This impressive chasm is one of the longest natural underground cavities in the world.

Ancient paintings known as the "Sistine Chapel of Cave Art."

A stunning 18th-century site where pilgrims ascend by a series of punishing stairs only to return via funicular.

An Antoni Gaudí masterpiece in Astorga.

Thanks to an acoustic anomaly, this unassuming stone bench has heard one hundred years of secrets.

An accidental trick of light casts the perfect shadow of a pilgrim of the Camino de Santiago against the cathedral wall.

The oldest Roman lighthouse still in use.

This beautiful spit of land was once the summer playground of the king of Spain.

Giant topiary dog once played a role in a terrorist bomb plot.

Two towns are linked by an engineering marvel masquerading as a boring suspension bridge.

The most elaborate of 12 medieval arched doorways to the old city of Burgos.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

These Stolpersteine located in Spain honor Republican soldiers who perished at the hands of Nazis after the fall of France.

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

A beautiful little museum hidden away in the heart of Barcelona holds a treasure trove of Ancient Egyptian artifacts

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.