This colorful statue welcomes visitors to a Barcelona park.

A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

A temple to modernity, tucked away amid Barcelona's more well known museums.

Bask in the 19th century grandeur of an eccentric Freemason millionaire's private gardens.

A cemetery in Barcelona's Poblenou district is home to this touching funerary statue, which depicts death in the form of a winged skeleton.

A once grand hotel now sits eerily abandoned in the Catalan countryside outside Barcelona.

A gravity-defying "devil's bridge" that has a surprising architectural feature for its stability.

Two well-hidden huts let animal lovers spend the night among the bears, wolves, and other predators of the forest.

The stunning remnants of this wreck emerge from an otherworldly backdrop of rainforests.

The Brutalist building harbors an unusual inverted dome that swoops down over its central sacred room.

Housing the famous Norwegian ice-defying 19th century polar exploration ship.

A stunning architectural yet functional feat, towering over Oslo.

The final resting place of many of Germany's most famous communists.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

Super-heavy Nazi architectural experiment.

What started as a tongue-in-cheek shrine is now a full-blown museum celebrating "The Hoff" and his longtime love affair with Berlin.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

A museum dedicated to the history of a terrifying secret police is now held in their former headquarters.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

An incredibly well-preserved piece of ninth-century Viking poop.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

This doorless 20th-century elevator doesn't stop or slow down.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.