At 824,292 km2 (318,261 sq mi), Namibia is the world's thirty-fourth largest country (after Venezuela). After Mongolia, Namibia is the second least densely populated country in the world (2.7 inhabitants per square kilometre (7.0/sq mi)).
The Namibian landscape consists generally of five geographical areas, each with characteristic abiotic conditions and vegetation with some variation within and overlap between them: the Central Plateau, the Namib Desert, the Great Escarpment, the Bushveld, and the Kalahari Desert.
The Central Plateau runs from north to south, bordered by the Skeleton Coast to the northwest, the Namib Desert and its coastal plains to the southwest, the Orange River to the south, and the Kalahari Desert to the east. The Central Plateau is home to the highest point in Namibia at Königstein elevation 2,606 metres (8,550 ft). Within the wide, flat Central Plateau is the majority of Namibia’s population and economic activity. Windhoek, the nation’s capital, is located here, as well as most of the arable land. Although arable land accounts for only 1% of Namibia, nearly half of the population is employed in agriculture.
The abiotic conditions here are similar to those found along the Escarpment; however the topographic complexity is reduced. Summer temperatures in the area can reach 40 °C (104 °F), and frosts are common in the winter.
The Namib Desert is a broad expanse of hyper-arid gravel plains and dunes that stretches along the entire coastline, which varies in width between 100 and many hundreds of kilometres. Areas within the Namib include the Skeleton Coast and the Kaokoveld in the north and the extensive Namib Sand Sea along the central coast. The sands that make up the sand sea are a consequence of erosional processes that take place within the Orange River valley and areas further to the south. As sand-laden waters drop their suspended loads into the Atlantic, onshore currents deposit them along the shore. The prevailing south west winds then pick up and redeposit the sand in the form of massive dunes in the widespread sand sea, the largest sand dunes in the world. In areas where the supply of sand is reduced because of the inability of the sand to cross riverbeds, the winds also scour the land to form large gravel plains. In many areas within the Namib Desert, there is little vegetation with the exception of lichens found in the gravel plains, and in dry river beds where plants can access subterranean water.