Mound B is the oldest mound at Poverty Point, and radiocarbon dating of charcoal from it indicates that construction began about 1600 B.C. Today it is about 20 feet high and 180 feet in diameter at its base. It originally had a perfect conical form, but archaeological excavations in 1955 inadvertently altered its shape. Before construction began, the topsoil was removed. The mound was then built in seven stages, including three major flat-topped platforms of silt loam. The floors of those platforms contained firepits, charcoal, and possible postholes, indicating that some activities took place there. In the final stage, a conical silt-loam mantle was placed over the entire mound to give it its final shape. Impressions left in the mound fill by woven baskets and skin containers used to haul dirt have helped archaeologists better understand ancient earth-moving techniques. Although conical mounds in the southeastern U.S. are often burial mounds, Mound B is not one, and understanding how it was used will require future research.