The Sacred Valley of the Incas was undoubtedly a key area of settlement to the Incas. Its agreeable climate and fertile plains make a rare and fruitful combination for the high Andes. It was also the route to the jungle and therefore an area with access to the fruits and plants of the tropical lowlands. The Sacred Valley served as a buffer zone, protecting Cusco from incursions of the Antis, the fierce jungle tribes who from time to time raided the highlands. Today the Sacred Valley remains a lush agricultural region supplying the city of Cusco with much of its produce such as maize, fruit and vegetables. Most people visit the Sacred Valley as part of an organized one-day Sacred Valley Tour. http://www.andeantravelweb.com/peru/destinations/cusco/sacredvalley.html