Nishapur is known to have existed as a settlement for at least 1500 years, though it is believed to have experienced more cycles of destruction and reconstruction in that time than even its more ancient neighbors. During its peak in the 11th century, it was one of the largest cities on earth, rivalling Baghdad in importance. Several dynasties claimed it as their capital, and until its destruction by the Mongols in the early 13th century, it drew scholars and administrators from around the Muslim world. To this day Nishapur is famed for its namesake nish, the brilliant turquoise mined in the surrounding hills. The distinctive color of many Central Asian exterior tiles is owed to turquoise from Nishapur, and the city has long been a center for tilemaking and ceramic arts.