The perfectly preserved underground rooms where Churchill plotted the war against Germany.

The celebrated eyesore created by starry-eyed sweethearts.

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

An ancient ossuary in Rouen.

A magical, macabre wax museum, beloved by locals, uses real artifacts to depict an assassination from the French Revolution.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

A natural arch carved by a river gave its name to the so-called "Cave of Forgotten Dreams."

The world's tallest bridge is also possibly the most elegant.

Historic medieval fortified city in southwest France.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

This 600-year-old home seems to defy physics.

Soaring over 6,000 feet in the Bavarian Alps, this beer garden was once Hitler's 50th birthday present.

The fairy tale castle of the "fairy-tale king."

Each time a baby is born in Ghent, these streetlights flash in silent celebration.

A moving memorial to the fallen and missing from WWI trenches.

Brussels' favorite peeing boy has a sister.

Christ's blood preserved in a Belgian town.

A little sculpture with a large wardrobe.

The prototype for all Nazi concentration camps.

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.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

The last bastion of Roman presence north of the Alps looms over a German town.