The enormous isokinetic structure hangs within a science center in Estonia.

The secret cells in the basement of the KGB's Estonian "Grey House" have been preserved as a grim Cold War museum.

A beautiful footbridge with over 2,000 glass sculptures along the walls and ceiling.

The only surviving piece of a submarine said to be the most decorated vessel in U.S. history.

The first park built over a freeway is a brutalist masterwork.

The longest and widest floating bridge in the world.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

The classic Atari game's iconic aliens have invaded downtown San Diego.

A sculpture of the famous photograph stands on San Diego's "Greatest Generation Walk."

This futuristic bridge is one of the longest self-anchored pedestrian bridges in the world.

This Pringle-shaped ledge makes for the perfect photo op.

An historic and oft-filmed spot for musclebound iron pumpers on the Pacific coast.

60 feet of towering steel balances gracefully.

The largest collection of two headed animals in the world.

A roadside music shop featuring a confounding series of folk art installations.

Once a gas station, this flightless airplane beside the Old Dixie Highway now houses a barbershop.

This landmark is a central figure in the Nez Perce origin story.

This inanimate goat created by the "welding nun" has been helping to clean up the city of Spokane for more than 40 years.

The decorations were inspired by an unlikely missing treasure.

This playground sculpture of an icon from the past is dedicated to the children of the future.

This improbable contraption was passed down through five generations of industrious Tennesseans.

San Francisco's newly reopened hands-on science museum.

This concrete tangle of square pipes has stood as a proud thorn in the city's side since the '70s.

A bust of Franz Kafka spins in pieces, reflecting the writer's inner torment.