9. Nazca Lines
In the Nazca Desert of Southern Peru there are a series of glyphs that have been drawn on the ground that resemble a number of objects including birds, spiders, monkeys, and flowers. Since the glyphs are only visible from high above the ground, it is not understood how an ancient culture could create such precision drawings on such a large scale. Scientists believe that they were created by people of the Nazca culture between 400 and 650 A.D. There are a number of theories as to why they were created and how, but none of them is known to be factual.