Limited agriculture was probably also undertaken on the terraces. The entire site was apparently subdivided into barrios focusing around a center of public architecture consisting of elites residences and and public areas for ritual activities all evidenced by largely unexcavated mounds. The unique size and architectural elaboration of the Main Plaza and and the fact that there are 14 structures surrounding it suggest that it may have played a role in integrating the activity of the barrios . Nor is there firm evidence of manufacturing activity duriing this period. Both open and semi-closed household units are observed in IIIA with considerable variation in the form of the latter.
Little variation is apparent among households in burials or artifacts.
The closed household units of this phase exhibit significantly more standardization in size and morphology than do those of earlier phases. Winter s types will however serve to illustrate the diversity of residential architecture. This difference in type of residential structure provides some evidence for the existence of a social class structure characteristic of state level societies . However, in view of the variety of residential types, it is difficult to draw firm conclusions about the nature of this structure from this data alone. Ethnohistorical data from the conquest period suggest that there were basically two socail strata in Zapotec society with less important sub-divisions within each.