Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

A medieval church built up to defend its village.

A Romanian church built from one single oak.

Something's watching you.

Packed to the ceiling with antique taxidermy and hunting arms.

A stunning 18th century pharmacy and medieval chemist's collection.

Some call this eerie forest of crooked trees the "Bermuda Triangle of Romania."

The Natural History Museum that time forgot.

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

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

Swedish skyscraper with a 90° twist.

This chimerical bridge/tunnel appears to dead end right into the sea.

Stockholm's narrowest alley is barely over two feet wide.

Religious structure known for its sculpted details.

The ancient Greek Titan guards this massive dam holding a lightning bolt to symbolize electricity.

This hauntingly beautiful cemetery outside a medieval citadel is full of winding paths and ivy-covered graves.

Nine centuries-old fortresses guard the walls of this medieval Romanian city.

Romania's only crater lake with water as pure as if distilled.

This snug medieval lane is one of the narrowest streets in the world.