Flying over the high plateaus of Peru, one can discover an archaeological treasure traced on the ground and classified as a World Heritage Site by UNESCO : the Nazca geoglyphs. These gigantic drawings represent animals, geometric or humanoid figures. But what do they mean ? Why did the Nazcas draw these extraordinary designs, some of them over a half of mile high ? How did they do it since they had no way to get up in the air to get a bird's eye view ? When the Nazcas were a prosperous people, why did they abandon their plateaus, leaving behind their drawings and burying their pyramids ? Why does a civilization die out ?