This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.

Birthplace of the "Cat in the Cradle" and a cluster of iconic, original windmills that let the Dutch tame the seas.

An Amsterdam street lined with antique shops each one dedicated to a different obscure collection.

A rare example of World War I trenches from the British front.

A symbol for the opposition to nuclear power around the world.

A public display of random paleontology.

This colorful artistic feature atop a Danish art gallery allows visitors to stroll through a rainbow.

Two massive boulders, rocking back and forth with the ebbing of the sea.

This remote island village was in danger of depopulating completely until a tunnel was built to connect it to the rest of the world .

The largest lake in the Faroe Islands seems to be held hundreds of feet above sea level thanks to an optical illusion.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

You would never come across this tiny green oasis if you didn't know it existed.

This whimsical statue dumps water on its head to symbolize knowledge flowing into his brain. Or maybe booze.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

The most visited, and possibly most controversial, museum in Germany.

The "stairway to heaven" lookout tower was built to resist weather, arson, and the laws of physics.

A monument to the man who almost killed Hitler.

The walls of Germany's Parliament still show the scars of the Red Army takeover in World War II.

The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

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".

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

A statue of the second-tallest Dutchman in history.

Rotterdammers' dirty minds gave this santa a dirty nickname and cursed it to a life of wandering.