Namib sand sea and Kuiseb river from the Air. Kuiseb River stopping the dunes, as seen from the air. Here we show that the longitudinal dunes of the Namib Sand Sea (visible as red-orange near the horizon to the south) do not continue past the Kuiseb river despite sand transport in the south-to-north direction. The dark material is vegetation that lives in the channel bottom even though the river flows only a few tens of days per year on average. The nearfield desert north of the riverbed is devoid of sand cover. The Gobabeb Desert Research Station is visible at the right, near the river.