A Neolithic culture (c 7000-3500 BC, some say Middle Neolithic c 4200-3700 BC) in lower Danube valley of southern Romania and characterized by terrace-floodplain settlements, consisting at first of mud huts and later of fortified promontory settlements of small tells. The Boian phase was marked by the introduction of copper axes, the extension of agriculture, and the breeding of domestic animals. The distinctive Boian pottery was decorated by rippling, painting, and excised or incised linear designs with white paste. Intramural burial is most common, but occasional large inhumation cemeteries are known. By spreading northward into Transylvania and northeastward to Moldavia, the Boian culture gradually assimilated earlier cultures of those areas. Flourishing exchange networks are known to involve Prut Valley flint, Spondylus shells from the Black Sea, and copper.