The site sits inside a rath, a type of circular earthen enclosure built during the early medieval period, typically as a farmstead or defended settlement. The reuse of such enclosures for burial was not uncommon in Ireland, particularly for the interment of unbaptised infants. These burial places, sometimes called cillíní, existed outside the sanctified ground of parish churchyards, a consequence of the Catholic Church's teaching that unbaptised children could not be buried in consecrated soil. The ground here at Coolbeg carries no enclosing wall or boundary feature of its own; it is defined only by the arrangement of the stones themselves. According to local information, the last burial took place around 1900, which means living memory was not so very far removed from the practice when it finally ceased here.