A small square plaque marks a failed assassination attempt that could have changed history.

A floundering Polish shipyard was once the soul of the Solidarity movement that capsized communism.

A one-of-a-kind sundial at the Very Large Array honors a radio astronomy pioneer, incorporating the original piers from his breakthrough radio telescope.

The birthplace of most all of Europe's space missions is here on the Dutch coast.

The NASA scientists behind Apollo 11 started out developing Nazi weapons at this abandoned German rocket factory.

The remains of a grand castle that may have inspired Bram Stoker's Dracula.

The ruins of this gorgeous clifftop castle look like something from a fantasy novel.

A historic ruin just 20 feet away from a busy highway onramp.

A plaque installed underwater marks the fall of a royal family from an imagined parallel universe—part of a globe-spanning art project.

Overlooking a Scottish loch, this beautifully crumbling castle once inspired a poem by William Wordsworth.

Brought to you by the makers of fiberglass dinosaurs.

One of the largest amphitheaters in Europe is a former Nazi gathering place that still stands today.

The footprint of a frustrated devil in Munich's Cathedral.

Golden cobblestones remember a time when this small alley was used to avoid having to give a Nazi salute.

These bronze pamphlets remember a remarkable group of Germans who fearlessly opposed the Nazis in the very center of their power.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

Vietnam's feral abandoned water park offers access to a post-apocalyptic funscape, now with fewer crocodiles.

Repurposed space and ultra-modern construction collide to create this geometric wooden spectacle.

This giant urban staircase was built to keep the city's brave fighting men from getting waylaid in the red light district.

What was once a bustling mining installation is now a bustling hub of contemporary art.

The mysterious round rocks of Schooner Gulch.

According to the locals, the sands of this secluded Norway beach are infused with gemstone particles.

Mysterious man-made rock piles form an ancient cemetery on this rocky beach in Norway.

The mark of the Devil's horns on a marble column in Milan.