Bouar megaliths

The Bouar region lies in the prefecture of Nana-Mambéré, about 450 km west of Bangui. The monuments stand on the watershed between the basins of Lake Chad to the north and the Congo to the south. The megalithic zone extends 130 km in length and 30 km in width, and the sites are concentrated in three areas, Moni, Ndio and Bouar, all at the edge of the secondary forest.

The tazunu are artificial mounds on which many blocks of cut granite were set upright. The number of standing stones per monument varies from two to more than a hundred. The mounds are bordered, depending on the case, by niches or by dry-stone cists. The standing stones appear to be grouped and aligned across each site, and in 70% of cases their profile is oriented from north-east to north-west.

Pierre Vidal, confirmed by later work, distinguished two main categories. Monuments with internal alignments have small standing stones, about a metre high, set in lines or sometimes in corridors; those bordered by rows of open vaults, such as Tazunu Beforo and Gam and the three Tazunu Tia, belong here. The second category has a mound of dry stones on which granite stones were raised and which is bordered by external vaults; Tazunu Zupaya and Be Yolé belong here.

The stratigraphy, the same for all monuments studied, comprises four layers from top to bottom: a humus layer, a layer of stones, a layer forming an archaeological horizon at the base of the monument, and a lateritic layer with quartz flakes. The material contained in the monuments is very scarce: fragments of pottery, a few pieces of slag, stone objects and rare iron objects. No bones survive, because the acidity of the soil has dissolved them.