Turpan Depression, satellite image. North is at top. The Turpan (or Turfan) depression (lower frame) is located at the foot of China's Bogda Mountains (green, upper frame). The depression is a strange mix of salt lakes (blue), sand dunes (orange), and vegetation (dark green), and is one of the few areas of land in the world that lie below sea level. Bare land is shown in pink. The area shown in this image is around 160 kilometres wide. The image data includes infrared wavelengths, and was obtained on 1 September 1999, by the Landsat 7 satellite.