This man-made mound monument was built out of soil from all across the Polish empire.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

A marvel of technology a century ago, this disused power station now offers a lovely glimpse into the industrial design of the past.

This statue of a falling man commemorates a teenage martyr of the Hungarian Revolution.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

Possibly the world's largest hourglass only needs to be reset every New Year's Eve.

A museum in the childhood house of a medical pioneer.

The abandoned "Red Star Train Graveyard" is the final rusting place for precious artifacts of train history.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

Once the home of a hermetic monk, this cave now houses a small church.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A monument to the three wars that led to German unification towers within a Berlin traffic circle.

A towering monument to war, located on a beautifully peaceful hill.

One of the world's heaviest musical instruments towers within a popular urban park.

Known simply as "The Hand," this famous public sculpture in Berlin was featured in a Depeche Mode music video.

Cold war icon and onetime "hole" in the iron curtain.

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.

This conical hill was built as a testing ground for an engineer known as the Glider King.

Berlin's old airport.

Beneath the impressive baroque cathedral that rises from the center of Berlin lies the largest collection of Prussian royals in the world.

Home to 10,000 medical specimens including the remains of Rudolf Virchow's extensive collection of pathological specimens.

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.