Engaruka
Engaruka is an abandoned system of ruins in the Great Rift Valley of northern Tanzania (2°58′58.80″S 35°57′0.00″E / 2.9830000°S 35.9500000°E). Situated in the Arusha province, it is famed for its irrigation and cultivation structures. It is considered one of the most important archaeological sites in the Great Lakes region.