Image Caption: Great numbers of circular, center-pivot irrigation plots appear in this west-looking view of northern Saudi Arabia (center to lower left). The entire country between the shifting sands of the Ad Dahna Sand Sea (light colors center and right) and the almost soilless Nejd Plateau (left) has been darkened by thousands of these agricultural fields. The Nejd Plateau is a mass of dark rocks, some volcanic, in northwest Saudi Arabia. The sweep of the Ad Dahna Sand Sea is one of the major features of Saudi Arabia (center and right) as seen from the orbiter. The dunes follow the trend of regional winds (northwesterly in the center of the view) which circulates around the Nejd plateau. The north end of the Red Sea can be seen top left with the Sinai Peninsula and Mediterranean are just visible center top. Iraq is under clouds top right.