WWII rocket launchpad in rural Germany and site of operation backfire.

The only remaining U-boat that is still floating never actually saw any action in World War II.

The portrait of a man from Japan who sent weekly letters to a Dutch hotel he never visited.

Two gravestones clasp hands over the religious divide.

The world's oldest rose is so tough it survived being bombed in World War II.

This incredible stone temple is a monument to death, victory, and fantasy architecture.

One of the most iconic neon ads of former East Germany.

Pick up this rock and become an instant legend.

A 246-foot-high revolving restaurant rises unexpectedly from a forested Finnish hilltop.

A naturally occurring tunnel in this Nordic mountain makes it look like it's been shot.

The rusted hull of a WWII German destroyer pokes above the surface in a Norwegian fjord.

The wilderness of northern Sweden is full of shelters to protect people from sounding rockets returning from space.

The deepest hole drilled in the name of science, where evidence of Precambrian life was found.

This cairn marks the only place where Central European Time, Eastern European Time, and Further-eastern European Time meet.

This small Bavarian graveyard is filled with empty graves for German soldiers lost during the World Wars.

A mysterious, weather-beaten bus lies on the coast of Harris, enticing the curious to investigate.

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

An ornate century-old elevator still connects the two halves of Bad Schandau.

This still-celebrated home was a radical architectural experiment in 3D De Stijl.

A monument hidden in the woods built in 1938 as a getaway for a Dutch museum curator.

This gigantic monument hidden in the woods was built to thank the Dutch for sheltering Belgian refugees during World War I.

These tenacious 14th-century towers defied demolition and are now a fairytale vacation rental.

There are two dozen tanks just sitting in an open field in Lower Saxony.

The tallest waterfall in the Netherlands is a lovely, stepped feature that is only 50 feet tall.