A light-colored slurry plaster marks the outlines of earthen walls exposed through excavations at Mound 7, Ngre Kataa. View looking eastward. The L-shaped juncture where two walls intersect is visible (bottom). The interior and exterior of the walls were coated with a thin plaster, appearing as a light-colored thin line exposed by archaeologists as they dug down. A two-meter scale appears (left). To the right and outside the building is a cluster of stones, some perhaps used in food processing activities. Ngre Kataa, 6 June, 2009.