A factory director designed what was the world's longest suspension footbridge in 1923 so his employees could get to work safely.

Crossing this suspension bridge feels like walking through the sky, a fitting tribute to the head of the Apollo program.

A marble Lucifer hides behind the pulpit of this Gothic cathedral.

Climb to the top of its spiral spire for spectacular views of Copenhagen.

Double spiral staircases are not unheard of, but they are very rare.

Climb this overlooked gem's spiral staircase and you'll be rewarded with spectacular views of Glasgow.

The Swiss artist's bulbous and overgrown shape-shifting sculpture controversially graces the center of Bern.

Conspiracy theories and occult legends surround this mysterious natural rock formation.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

This enormous spiral sculpture looks strangely out of place on the edge of a housing development.

An architectural oddity of six stories, accessed by graceful ramps.

Built to test magnetically levitated elevators, the tower also boasts Germany's highest visitor platform.

A corkscrew-shaped barn in Ireland.

This palatial spiral staircase was so unusual the name "snail" was given to the noble family who built it.

The ancient tomb acts as a calendar that keeps perfect time.

A spiral staircase twists to the top of this unusual Czech lookout tower.

This dramatic landscape hidden on the Isle of Skye looks as though you've stepped into the magical realm.

A long spiraling walkway winds through the woods, and around a copper beech tree at the center.

A lavish 16th-century mansion filled with spectacular staircases, fantastic frescoes, and gorgeous gardens.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

An abandoned stretch of elevated road in the middle of the Brazilian jungle.

This abandoned bridge to nowhere stands secluded in the woods of a Cleveland suburb.

At high tide this strange footbridge appears to have no purpose whatsoever.

Volcanic rocks ground down into sand make this Spanish beach as black as night.