The necropolis, which dates back to the Middle Neolithic (c 4,500 BC), consists of elongated structures made from earth and wood, ranging in size from 12 metres to 300 metres in length. The monuments are surrounded by ditches, which range from 20 cm in width to up to 15 metres, and which may have once held wooden fences. The fact that the tombs range in size from small, simple burials to large and more elaborate constructions, suggest that their society had a hierarchical structure.