The Nasca Lines are one of the world's great enigmas. Who etched the more than 1,000 animal, human, and geometric figures that cover 400 square miles of barren pampa in southern Peru? How did the makers create lifelike images of monkeys, birds, and spiders without an aerial vantage point from which to view these giant figures that stretch across thousands of square yards? Most puzzling of all, why did the ancient Nasca lay out these lines...