A storm shelter built for survivors of shipwrecks.

A collection of short standing stones covers this hillside.

A German “baron” built this castle for his wife, but their romance was short-lived.

This large open-air museum showcases the ordinary lives of the people of the Netherlands and pre-industrial crafts and practices.

A large measuring stick marks the lowest point of a country that is partially under sea level.

The struggle of a small Dutch island against the sea.

Hop aboard a charming bog train to explore this rare open-air museum of peat.

Strange secondhand shop showcasing taxidermy and oddies

Incredible labyrinth of man made caves.

The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

Europe's official "zero-level," the equator of elevation.

Amsterdam's former hotspot for public executions and dissections.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

Catch a scenic view of Warsaw's Old Town from the top of a centuries-old dumping ground.

These plaques found across Warsaw commemorate the sites where executions or battles took place during the German occupation.

A tribute to the Polish insurgents who fought in the failed attempt to end their city's Nazi occupation.

Warsaw's fantastically preserved gasworks...almost.

A larger-than-life statue of the German revolutionist stands proud in a small town where he never lived.

Bohemian paradise covered in majestic forests.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

China's most famous acrobatics act.

Two Chinese dragons guard the caves of this medieval temple in Iran.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.