BÉNIN  
Projet benino-danois d'archéologie (BDArch)

The subterranean structures, which early got the shorthand notion of "caves", consist of several architectural elements. Basically, they have a round or crescent entrance, ca. 1 m in diameter, a shaft of varied length, which leads to the central chamber. The later can be round or elongated, seldom reaching more than 5 m in diameter. It frequently acts as the antechamber for several side-chambers. The height of the chambers is not exceeding 3 meters. In rare cases the caves are interconnected.

989 caves (70 cave sites) have been registered in a course of research. Variations of cave architecture have provided grounds for separation of four main types, which apparently also reflect a temporal distinction.

The most ancient caves are the most complex ones. These possess an elongated or kidney-like central chamber with up to 5 side-chambers. Different niches and protruding steps make this elaborate architecture stand out in the total mass of caves.

Fig. 6. The most complicated type of caves is named after the village Kana Hadagon.

Gradually the number of architectural elements decreased resulting in the development of a cave layout similar to that of wells or cisterns. This architectural development probably resembles functional developments as well. The original idea of constructing the caves as hiding places to be used in times of military unrest was transformed with time. The simplest type of caves with a long shaft and just one central chamber could therefore have been constructed for collecting water during the rainy season (Fig. 7). In fact, caves of all types seem to have been in use at some point in time for collecting water.

Fig. 7. These ampoule-like caves can number up to several hundreds in one locality.

Cisterns with a somewhat similar layout known from neighboring countries like NE Ghana have been found in low-lying areas, apt for collecting water. By contrast, the beninoise caves of the simple ampoule-like type may still have been created with the intention of carving basements. This is demonstrated by their topography, where higher places were preferred to lower ones, the former at least partly preventing the flow of water and mud into the caves.