After being lost for decades, this striking mural depicting the atomic bomb covers the wall of a busy Tokyo metro station.

A rare, flower-shaped example of Brutalist architecture in Switzerland.

Hidden in plain sight, this creepy sculpture watches from above.

The weathered grave of a medieval anchoress who walled herself up in a cell attached to a church.

A 26-foot shark sculpture—a statement about bombs—set off a municipal battle royale.

One of Europe's oldest libraries.

A Victorian park cemetery, standing on the site of what was once the Great North Wood.

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

This Nazi ruin was the site where Hitler was almost blown up by a suitcase bomb.

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

The world's newest astronomical clock is also its most accurate.

This tower in a small Polish village uses the power of a sacred bell to ward off mischievous weather spirits.

The world's greatest slide descends 18 stories from this looping mountaintop viewing platform.

A fairytale Gothic castle steeped in Nazi treasure conspiracy theories.

A mysterious structure left behind on the Polish mountainside, sometimes called "Hitler's Stonehenge".

The unsettling remnants of a torn down movie set lies nearby the ruined location of the actual Płaszów Labor Camp.

This uber-quaint Polish village is known for its habit of painting elaborate floral motifs on just about everything.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

A striking public sculpture representing the period of martial law in Communist Poland.

These mechanical goats first battled it out in the year 1551, all because of an overcooked deer.

The traditional Polish croissant, folded 81 times into the shape of a horseshoe, is a legally protected cultural treat.

One of only two places in the world where two rivers cross each other without the waters mixing.

An abandoned Nazi explosives plant founded by the inventor of dynamite is now an underground museum.

A statue honors the children who fought Nazis in Poland.