A deeply worn grinding stone (grindstone 1, NK-08-112) removed from levels 1-2, unit 44N 4W, Mound 6, Ngre Kataa, photographed at the side of the excavation unit. The grinding stone was found in association with other grinding stones, tuyere fragments and whole and partial pots. When found, the grinding stone was oriented with its working surface facing downward. It was located adjacent to a concentration of dark soil (feature 1) that contained abundant oxidized sediment, slag and broken pottery. Archaeologists interpret the features at Mound 6 as facilities used to make and process metals. Photo scale in 5 centimeter increments. Ngre Kataa, 2 July, 2008.