The largest bell in the world has been swinging high above a Cologne cathedral for almost a century.

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

A series of abstract, silly sculptures represent the works of a great modern classical composer.

A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.

This banal Parisian entranceway is not what it seems.

This surreal statue brings a famous French novel about a supernatural cad to arresting life.

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

Exquisite wall sculptures carved in secret by an early quarryman in an obscure corner of the Paris Catacombs.

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

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

Paris' linguistic guide to the international language of, yes, love.

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

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

Iceland's tribute to its thankless civil servants.

A bit of the Berlin Wall was gifted to the Icelandic capital to commemorate the 25th anniversary of German reunification.

This stunning concert hall has become a symbol of Iceland's national recovery.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Amsterdam's former hotspot for public executions and dissections.

This bird-loving brewery is situated in an old municipal bathhouse, nestled beside a 300-year-old windmill.