Round or oval-shaped, the grain barn foundations have an outer diameter of 2.3 to 3 meters, most of them with an inner diameter of around 2 meters.
The grain barns were found surrounding the ruins of houses as well as jade and stone workshops which dated back to the same period, says Ma Juncai, a researcher with the institute.
The grain barns, densely located in proximity, feature similar structures and sizes and substantial storage capacity, Ma says, adding that they were clearly built to store food.