In the period 65005500 B.C., a farming society emerged in northern Mesopotamia and Syria which shared a common culture and produced pottery that is among the finest ever made in the Near East. This culture is known as Halaf, after the site of Tell Halaf in northeastern Syria where it was first identified. The Halaf potters used different sources of clay from their neighbors and achieved outstanding elaboration and elegance of design with their superior quality ware. Some of the most beautifully painted polychrome ceramics were produced toward the end of the Halaf period. This distinctive pottery has been found from southeastern Turkey to Iran, but may have its origins in the region of the River Khabur (modern Syria). How and why it spread so widely is a matter of continuing debate, although analysis of the clay indicates the existence of production centers and regional copying. It is possible that such high-quality pottery was exchanged as a prestige item between local elites. The Halaf culture also produced a great variety of amulets and stamp seals of geometric design, as well as a range of largely female terracotta figurines that often emphasize the sexual features. Among the best-known Halaf sites are Arpachiyah, Sabi Abyad, and Yarim Tepe, small agricultural villages with distinctive buildings known as tholoi. These rounded domed structures, with or without antechambers, were made of different materials depending on what was available locally: limestone boulders or mud and straw. The Halaf culture was eventually absorbed into the so-called Ubaid culture, with changes in pottery and building styles.