The Nazca Lines, a series of enormous geoglyphs etched into a roughly 200-square-mile stretch of the Peruvian desert, have long mystified scientists. Created by pre-Inca people between the 4th century B.C. and the 10th century A.D., the early land art features straight lines measuring up to 30 miles long, geometric shapes ranging from triangles to trapezoids and spirals, and around 70 depictions of plants and animals.