A dune is a hill of sand built by either wind or water flow. Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water. 
 
Within the vast Namib Desert in Namibia, Africa, unique shapes and patterns form as the winds whip to transform, shape and move these majestic Namib Sand Sea dune-scapes. Scientists have deemed the Namib Sand Sea the oldest desert in the world and are one of the greatest moving sand seas on the planet representing a vast variety of dune types. The entire sand sea here covers around 35 000 square kilometers with dunes rising as high as 300 meters. 
 
The Namib Sand Sea is composed of two dune systems that have been superimposed on top of one another. One is a consolidated dune system that is estimated to be around 21 million years old and the young dunes have been active for around 5 million years. 
 
What rare form will these take on in another 5 million years? Only time will tell as the Dunes here constantly reinvent themselves while the constant wind and sand-slides alter their shape and location into magnificent designs and structures.