Cyril Ruoso / Coastal desert sand dunes, Swakopmund, Namibia

Theo Allofs / Red sand dunes covered with vegetation, NamibRand Nature Reserve, Namibia

Theo Allofs / Plain covered with fairy circles, NamibRand Nature Reserve, Namibia

Theo Allofs / Plain covered with fairy circles, NamibRand Nature Reserve, Namibia

Theo Allofs / Aerial view of transverse sand dunes, Namib Desert, Namibia

Theo Allofs / Aerial view of transverse sand dunes, Namib Desert, Namibia

Theo Allofs / Red sand dunes, Tsauchab River Valley near Sossusvlei, Namib-Naukluft National Park, Namib Desert, Namibia

Theo Allofs / Rock outcrop and red sand dunes near Sossusvlei at sunrise, Namib-Naukluft National Park, Namib Desert, Namibia

Theo Allofs / Sand dunes south of Hoarusib River, Namib Desert, Namibia

Theo Allofs / Sand dunes and Hoarusib River, Namib Desert, Namibia

Gerry Ellis / Northern edge of sand dune formation blocked by Kuiseb River, Namib-Naukluft National Park, Namibia

Gerry Ellis / Aerial view of transverse sand dunes, Namib-Naukluft National Park, Namibia