Great Salt Desert patterns, as seen from the International Space Station (ISS). The Great Salt Desert in Iran is an uninhabited wasteland of mud and salt marshes, covered with crusts of salt that prevent the last of the water evaporating. It is also called the Dasht-e Kavir, or Kavir Desert, and is the largest desert in Iran. The lack of soil and vegetation leaves rock layers clearly visible, forming large swirling patterns. A lake (dark blue) near centre fills an S-shaped area. The area shown in this image is around 105 kilometres across. Photographed by an Expedition 38 crew member on 14 February 2014.