In this paper, I outline the development of the 1st millennium BC settlement at Meillionydd near Rhiw on the Llŷn peninsula in northwest Wales, which evolved from an unenclosed cluster of roundhouses into a double ringwork enclosure embanked by two concentric drystone-faced earthen banks before being slighted and nearly completely flattened in what appears to be a rather labour intensive ‘closure’ rite. I then try to interpret the meaning associated with this process of enclosure and abandonment, and what it might tell us about the beginnings of a process of social evolution that turned the mostly egalitarian, kinship-based societies of the beginning of the 1st millennium BC into the highly hierarchised, aristocratic societies of the Welsh Middle Ages.