Turkestan is a historical region of west-central Asia extending east from the Caspian Sea into western China and south from the Aral Sea into Afghanistan. It has long been a crossroads for trade and conquest between East and West. The history of Turkestan dates back to the third millennium BC. Many artifacts were produced in that period, and much trade was conducted. The region was a focal point for cultural diffusion, as the Silk Road traversed it. Mausoleum of Khoja Ahmed Yasawi. is an unfinished mausoleum in the city of Turkestan, in southern Kazakhstan. The structure was commissioned in 1389 by Timur, who ruled the area as part of the expansive Mongol Empire.