In the Mandara Mountains of Cameroon live various ethnic groups commonly referred to as Kirdi; this particular group are the Mofou. Their buildings are created from the stone rubble that covers the Mandara mountain terrain. Much of the stone has natural fracture lines that tend to split into thick flat sheets. These ready-made bricks—along with defense needs—helped to inspire the construction of their huge castlelike complexes. But rather than the Euclidean shapes of European castles, this African architecture is fractal, with small circular granaries and larger circular granaries spiraling within 3 large stone enclosures, which themselves spiral from a central point (can you find the only square building?). There is a sort of recipe or algorithm that determines how the system expands to accomodate growth. It is determined by knowledge of the agricultural yield. This volume measure was then converted to a number of granaries and these were arranged in spirals. The design is not simply a matter of adding on granaries randomly, but rather the expansion of a quantitative and deliberate process.

Can you guess the purpose of the square building at center?