Striking occult iconography on a medieval German church.

An extraordinary mechanical calculator designed by the mathematician and philosopher Gottfried Leibniz.

WWII rocket launchpad in rural Germany and site of operation backfire.

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

Despite a legend that says this highest peak in Oregon was climbed in high heels, scores of people have died on its slopes.

The only road through the heart of Glacier National Park.

This amazingly preserved Gold Rush town is a historian's dream.

A stratovolcano located in the south of Iceland, with a long history of charted activity and a rich mythology attached.

World's strongest whirlpool.

The world's first and only escalator for lazy bicycles and their daunted riders.

A favorite with sightseers and locals alike, this Norwegian funicular provides easy access to a stunning view of Bergen and its environs.

It houses the remains of a 17th-century version of the Titanic.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Four alabaster giants contemplate the tides on the shore of Denmark.

This huge industrial sculpture looks like a UFO and a factory had a baby.

Tiring of digging out the door to this church for every service, it was eventually abandoned to the sands.

The northernmost point in Denmark is a turbulent sandbar created by two clashing seas.

Beneath Denmark's Højbro bridge, a bronze merman and his seven sons forever mourn for the mother and wife who left them for land.

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

Copenhagen's celebrated theme park and gardens.

Designed by Buckminster Fuller, this relic of the 67 Expo survived fire and ice.

The world's largest rotating world.

This tiny patch of arid sand sits in one of the greenest states in the United States.

This shifting North Carolina sand dune is an odd little desert surrounded by oceanic forest life.