Sometime in the 15th century, an Iron Age farming community built a large continuous village area on the footslopes of the Rift Valley escarpment, housing several thousand people. They developed an intricate irrigation and cultivation system, involving a stone-block canal channelling water from the Crater Highlands rift escarpment to stone-lined cultivation terraces. Measures were taken to prevent soil erosion and the fertility of the plots was increased by using the manure of stall fed cattle. For an unknown reason Engaruka was abandoned at latest in the mid-18th century. The site still poses many questions, including the identity of the founders, how they developed their farming system, and why they left.