Inca Terraces in Pisac, Peru. The terraces were built to make the most efficient use of shallow soil and to enable irrigation of crops. The Inca used a system of canals and aqueducts to direct water through the levels and increase fertility - See more at: http://dc-0ca72a33.inspirationgreen.org/terraced-farms.html#sthash.2GHX8Wa0.dpuf