The Ryn Desert or Ryn-Peski Desert (, Naryn-Qumy), is a desert in western Kazakhstan north of the Caspian Sea and southeast of the Volga Upland. The borders of the desert are very loosely defined. Some maps show the desert almost entirely within the Caspian Depression, stretching almost to the coast of the Caspian Sea, while others show it north of the depression. It lies west of the Ural River between 46° N and 49° N latitude, and 47° E to 52° E longitude. Temperatures can reach extreme highs of during summer and in winter it can drop to a low of .