The landscape is defined by an arid, harsh climate and a long geographical history. The western part of the country has a mixture of enormous sand dunes, open plains, rugged valleys, escarpments and mountains and it is here that the oldest desert on the planet, the Namib, is found. The eastern interior is a sand-covered, more uniform landscape and contains the country's second great desert - the Kalahari, a vast and sparsely vegetated savannah that sprawls across the border into South Africa and Botswana.
The flat vastness of Namibia's deserts is relieved by a belt of broken mountains and inselbergs (the highest is the Brandberg at 2 579m above sea level), deep dry river valleys that serve as linear oases, savannah and woodlands, and long stretches of sandy beaches along the dramatic Skeleton Coast.
All this is in contrast to the rich grasslands, and subtropical woodlands of the Caprivi area in the north-east, the mopane woodlands of Etosha National Park, and the rich coastal lagoons of the Atlantic Ocean on the western coastline.
The country's perennial rivers - the Zambezi, Kwando, Okavango and Kunene Rivers - also form its political boundaries. Of these, only the Orange is not situated in the higher rainfall area of the north-east of the country, with the wetter areas here gradually giving way to the arid regions further south and south-east: The Kalahari and Namib Deserts. The diversity of vegetation and wildlife mirrors this gradient, so that there is rich biodiversity and higher number of species in the north-east, and a comparatively lesser fauna and flora moving away from this area.
The arid regions are richest in endemism however; species like the Hartmann's mountain zebra, the Dune Lark and Péringuey's adder occur nowhere else on Earth and are spectacular examples of species that have adapted superbly to the harsh dry environment.
In the waterless west there is a web of ephemeral rivers, the guttural tones of names such as the Kuiseb, Swakop, Hoanib and Huab reflecting a changed ethnicity. These riverbeds can remain dry for years before turning into a rage of life-giving water in a matter of minutes after episodic rain falls in the catchment areas. Such sporadic events turn the brown, sandy landscape into swathes of green bursting with life. These river courses end their lives in the cold Atlantic Ocean, where upwelling centres create nutrient-rich waters filled with plankton and kelp that in turn feed a variety of fish species.
For a place that at first glance may seem lifeless, the reality is astonishing: approximately 4000 species of plants, 650 bird species and 80 large mammal species, of which 604 plants, 14 birds and 15 mammals are almost entirely endemic to the country, some extending marginally into southern Angola. Reptile species total 240 and, as is fitting for such a dry, hot place, sun-loving lizard species number 125, making this the richest lizard fauna in Africa.