The famous artist couple lived and worked here, in two different houses separated by a bridge.

Hidden inside this Arizona fast food franchise is an in-depth exhibit on the famed WWII counterintelligence program.

Mother Nature outdoes herself with this stunningly beautiful set of caves carved into marble.

Stenciled handprints and wall paintings dating back 10,000 years, some of the earliest forms of cave art.

Go surfing on this urban wave, "hacked" by local surfers.

This lovely little bridge hidden in a Switzerland gorge is essentially a fairytale.

These chunky stone towers out in Lake Michigan are the key to Chicago’s drinking water.

Scattered around Atlanta are little doors with big charm.

Spanish religion mixed with local architecture has yielded a network of churches unlike any other.

A sculpture of a giant hand reaches for the stars in the middle of the Atacama desert.

This Japanese-inspired labyrinth of hot springs is hidden in a Chilean forest.

70,000 empty bottles of Coke comprise an ad seen only from the air.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.

A memorial to the victims of Argentina's "Dirty War."

Guitar made of trees, dedicated to a man's lost love.

A record-breaking pool that uses computers to turn ocean water into cleaner, private swimming water.

A museum founded to reflect on and remember the human rights abuses under Chilean dictator Augusto Pinochet.

This New Orleans tree is filled with hidden chimes that produce a carefully tuned melody.

Site of a former hidden treehouse in New Orleans.

A small park on Bourbon Street features life-size bronze statues of New Orleans musicians.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

A late sculptor's last project was to turn this abandoned cement factory into a castle-themed amusement park.

Man-made geyser that rises to the exact height of the Gateway Arch.

An abandoned factory along the Mississippi coated by a giant mural.