The Sossusvlei, Namibia's famous highlight in the heart of the Namib Desert, is a huge clay pan, enclosed by giant sand dunes. Some of the spectacular hills of sand are, at a height of 300 metres, the highest in the world. Only after a heavy rainfall, which is a rare event in this area, does the vlei fill with water. As the clay layers hardly allow any water infiltration, a turquoise lake will remain for quite some time.
 

The Namib Desert

Nicknamed the world’s oldest desert, the Namib stretches along the coast of Namibia to form one of the most spectacular and richest deserts in the world. Gently sloping toward the Atlantic Ocean, it is patterned by a sea of giant red sand dunes, some that reach 1000 feet (305 m) high. Because of its long, stable climate over time, a number of species boast ancient origins. Others have evolved unusual adaptations to survive in the extremely harsh environment.

The Namib Desert has a fascinating array of bizarre plant (and animal) adaptations, surviving in sand dunes of all shapes and sizes and vast gravel plains stretching for as far as the eye can see. With ephemeral rivers flowing unexpectedly, dunes, plains and rivers have all become vital components of the oldest desert on the planet, in existence for at least 43 million years.
The dunes of the Namib desert have developed over a period of many millions of years. It is thought that the vast quantities of sand were deposited into the Atlantic Ocean by the Orange river. This material was subsequently moved northwards by the Benguela current to be dumped back onto the land by the surf.

The coastal dunes developed as a result of this and were shifted further and further inland by the wind. Wind continuously reshapes the patterns of the huge dunes of the Namib desert. It timelessly forces the grains of sand on the flat windward slope upwards to the crest of the dune. Here they fall down in the wind shade. The leeward slope is therefore always considerably steeper than the windward side.