This Envisat image, acquired on 4 July 2011, shows southern Namibia and northern South Africa on Africa’s lower-west coast. We can clearly see the sand dunes of the Namib Desert – considered to be the oldest desert in the world. To the south of the desert is the Sperrgebiet diamond mining area. Further south, the Orange River forms part of the border between South Africa and Namibia before emptying into the Atlantic Ocean at Alexander Bay, which is noticeable by a lighter green colour in this image.