The Sossusvlei, Namibia's famous highlight in the heart of the Namib Desert, is a huge clay pan, enclosed by giant sand dunes.

The immense, rich-ochre sand dunes at Sossusvlei are one of the most astonishing sights in the world. Their curving slopes rise to a remarkable 300m (100m higher than their nearest rivals in Arabia) and they just beg to be climbed.

Geologists say that this supreme desert covering most of the Namib-Naukluft Park could be the oldest in the world. The older the dune, the brighter the colour from slow iron oxidisation and a zillion minute fragments of garnet.

Visiting Sossusvlei takes some perseverance; it's 300km from the nearest highway, but well worth the effort. 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.