The rugged texture of the Altun Mountains (upper left) that forms part of the northern boundary of the Tibetan Plateau contrasts dramatically with the Takla Makan Desert of western China. Immediately north (to the right) of the mountains are large alluvial fans, gradually sloping downward in elevation. Sand dunes and sand ridges are visible along the northern (lower right) margin of the image. Click on photo for higher resolution. Image courtesy of NASA.