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
Kalahari Augrabies Extreme Marathon of 40 °C in the summer months and dropping to below 5 °C at night during the winter, presents a daunting challenge to the extreme athlete and determined adventurer alike. Known as the 'Big Daddy' in the South African running circles, the Kalahari Augrabies Extreme Marathon is event organised by Extreme Marathons, and has its place on the International Calendar of similar trail events. Participants run in the footsteps of the ancient Bushmen, through the fertile vineyards of the Orange River Valley (not in 2015), across rocky outcrops and into the desolate Great Kalahari Desert. Although the event is advertised