Andean ancestors living in Peru began to cultivate the potato 8,000 years ago. The Sacred Valley, with its fertile soil, gradually developed into an agricultural area, and terraces such as Moray and Pisac were formed. The valley can be regarded as the "Institute of Agricultural Science" of the ancient Incas. The advanced irrigation technology of the terraces enabled the Inca Empire to have enough food to feed a population of up to 12 million at its peak.