Dead Vlei, Sossusvlei, Namibia 2008.
The trees in this vlei are over 300 years old (and quite dead). Inland rivers were impounded by dunes as sea levels fell and eventually dried up. Today, after rainfall, the rivers run to the dunes and evaporate or go underground. Differences in dune colours are evident with heavier minerals (magnetite and iron oxide) depositing first and lighter coloured, less mineralized, dunes nearer the sea.