Merv was sacked by the Mongols.
Several cities existed on this site.
The site of Ancient Merv has been listed by the UNESCO as one of the World Heritage Sites.
... out with 22.3% under the age of 18, 8.0% from 18 to 24, 31.0% from 25 to 44, 21.9% from 45 to 64, and 16.9% who are 65 years of age or older. The median age is 39 years. ...