The last remnants of a massive medieval wall that once encompassed the city of Berlin.

A famed artist's inspiring work of peace and tolerance.

Visitors dating back to the 1600s carved their marks in the stones of the iconic tower.

Today this former Nazi concentration camp stands as a poignant memorial to the victims of fascism, and a warning from history.

The ruins of a military fortification sit atop this mountain.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

This famous archeological mystery may be an ancient example of movable type.

An early 20th-century bullring converted into a modern shopping center.

Giant eggs, walls of bread, and nightmare surreality mark the largest collection of works by Salvador Dalí.

Historic medieval fortified city in southwest France.

A 15th-century Corsican chapel that possesses a rare Catholic monument: a "Scala Santa," or "Holy Stairs."

Napoleon's childhood home is now open for people to explore the beginnings of France's short general.

A breathtakingly steep set of stairs is carved directly into the face of the sea cliffs of Bonifacio.

A gothic church dedicated to the love of wine.

Bordered by forest on three sides and the ocean on the other, the Great Dune of Pilat is the highest sand dune in Europe.

The eclectic observatory castle of a 19th-century astronomer and explorer.

Abandoned blockhouses from Nazi Germany's Atlantic Wall erode into the sea on a French beach.

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

This striking royal residence is the largest Renaissance-style castle in Scandinavia.

A perfectly circular stronghold constructed in the 10th century is now a nucleus of Viking culture housing a museum, village, and reenactment of an epic Viking battle.

This Danish rock field is actually a sprawling ancient cemetery holding the bodies of 700 Vikings.

A Gothic cathedral created from volcanic rocks.

Danish tourist destination well known for open stalls where vendors sell marijuana on the street.

Climb to the top of its spiral spire for spectacular views of Copenhagen.