It comprises the valleys of the Tekez (middle and lower portion), Kunghez, the Ili as far as the Russian frontier and its tributary, the Kash, with the slopes of the mountains turned towards these rivers.
The valley of the Kash is about 160 m.
The Avral Mountains, which separate the Kash from the Kunghez, are lower, but rocky, naked and difficult of access.
Moreover, the Babylonian inscriptions mention the Kashshi, an Elamite race, whose name has been equated with the classical KoQaaiot, Kiauuot, and it has been held that this affords a more appropriate explanation of Cush (perhaps rather Kash), the ancestor of (the Babylonian) Nimrod in Gen.
This central desert is the Kir, Kej, Katz or Kash Kaian of Arabic medieval geography and a part of the ancient Kaiani kingdom; the prefix Kej or Kach always denoting lowlevel flats or valleys, in contradistinction to mountains or hills.