Kalahari Desert northwest, forming marshes that are rich in wildlife. Ancient dry riverbeds—called omuramba—traverse the central northern reaches of the Kalahari and provide standing pools of water during the rainy season. A semi-desert, with huge tracts of excellent grazing after good rains, the Kalahari supports more animals and plants than a true desert, such as the Namib Desert to the west. There are small amounts of rainfall and the summer temperature is very high. The driest areas usually receive of rain per year, and the wettest just a little over . The surrounding Kalahari Basin covers over extending further into Botswana, Namibia
Libyan Desert Algeria. The sand seas contain dunes up to 512 meters in height, and cover approximately one quarter of the total desert region. Other features are the Aswad al Haruj (the "Black Desert"), a large circular region of black volcanic shield in the centre of the country, and the Hamada al Hamra (the "Red Desert") a rocky plateau to the west, on the Tunisian border, coloured by iron oxide deposits. To the southeast, between Kufra and the Libya-Egypt-Sudan border, lies the Jebel Arkenu, with the associated Arkenu structures, thought to be caused by meteorite strikes. North of the Gilf Kebir plateau,