Originating in the Ennedi Region of Chad Wadi Howar runs through the Sudanese states of North Darfur and Northern to join the Nile north of the great bend opposite Old Dongola.
Stretching over 1100 km[1]: 25 in west–east direction across the southern fringes of the Libyan Desert, it ordinarily receives 25 mm of rainfall per year.
At that time, savanna fauna and cattle herders occupied this region and the southern edge of the Sahara was some 500 kilometres (310 mi) further north than it is today.
[1]: 28 Abundant prehistoric sites certify Wadi Howar as a once ecologically favoured area of settlement and a communication route between the inner regions of Africa and the Nile Valley.
[1]: 31 The hitherto most thoroughly investigated archaeological site in the wadi is Gala Abu Ahmed.