3. Nazca Lines, Peru
You think crop circles are cool? Wait ’til you see the scope and complexity of the Nazca lines, 200 miles south of Lima. You have to get on a small plane to really appreciate a bird’s eye view of these impressive forms. Shapes of hummingbirds, spiders, llamas and lizards are carved into the land like enormous geo-graffiti. Alien theories abound, but most archaeologists believe they had something to do with water rituals for irrigation purposes. Still, how they were designed and executed with such precision is a head-scratcher. The Nazca lines were designated a World Heritage site in 1994 and are a must-see side trip when visiting Peru.