NAMIBIA // It is at Sossusvlei that the world's oldest desert is arguably at its most stunning. Sossusvlei is a large ephemeral pan, surrounded by dunes rising over 300m (985ft) high, sculpted by the wind into seemingly razor-sharp crests. At sunrise and sunset, the play of light is mesmerising, as the orange hues of the dunes are juxtaposed against the black shadows of the low-hanging sun. On the rare occasions when the Tsauchab River has enough water to fill the pan, the parched expanses turn into a striking blue-green lake that attracts abundant birdlife. Nearby in Deadvlei, the barren branches of ancient camelthorn trees make stark silhouettes against the white ground and blue sky.