Neolithic culture (c. 8th–4th century BC) centred in what is now southern Romania; it was characterized by terrace settlements, consisting at first of mud huts and later of fortified promontory settlements. 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. By spreading northward into Transylvania and northeastward to Moldavia, the Boian culture gradually assimilated earlier cultures of those areas.