Merw, located at the former banks of the Murghab River, was the most important Silk Road hub in the region, and particularly thriving as regional capital under Seljuk governor Sanjar.

Merw is the collective name of five urban centers that existed under various different names in different periods of time from the VI c BC up to the XVIII c AD. The entire 120 ha site of Merw has been recognized as a UNESCO World Heritage Site since 1999.