Brought to the Sahara following the Persian conquest of Egypt, the spread of a new irrigation technology allowed Garamantian civilization to expand dramatically The earliest evidence of a unique Garamantian culture comes from the settlement of Zinkekra, located at the top of a rocky plateau near the Wadi al Ajal. However, settlements gradually drifted further down the valley.   The location at the bottom of these valleys allowed new Garamantian settlements to better take advantage of a technology recently brought to North Africa with the Persian conquest of Egypt. Known as Qanats, or Fouggaras in North Africa, this advanced irrigation technology allowed Garamantian settlements to tap into groundwater reserves without the labor intensive practice of extracting water from wells with buckets. Instead, gravity brought water through the slightly inclined channel and delivered it to the irrigated outlet