That sunken quality, combined with what the site actually is, gives it a quiet unease. The Ordnance Survey maps of 1841 to 1842 recorded it as a circular area and labelled it plainly: "Burial Ground for Children."

Sites of this kind are known in Irish as cillíní, or sometimes as killeens, informal burial grounds used for centuries to inter unbaptised infants and others, such as the shipwrecked or the excommunicated, who were excluded from consecrated ground. The theology that drove this practice held that without baptism a child could not enter heaven, and so could not lie in a parish graveyard. These places tend to appear at the margins, physically and socially, often on older, pre-Christian earthworks. The enclosure at Kilcock fits that pattern. It measures roughly 40 by 21 metres internally and just over 45 by 39 metres externally, suggesting a substantial surrounding bank. In the north-western sector of the interior there is a small mound, four metres square internally, whose purpose is not recorded with certainty. A possible entrance, about four metres wide, opens to the east. What the nineteenth-century cartographers mapped as a neat circle has shifted in shape over time, or perhaps was never quite as regular as their conventions implied, and the enclosure as it now stands is noticeably uneven in outline. Whether the earthwork itself predates its use as a burial ground is not documented, but the reuse of ancient enclosures as cillíní was common across Ireland, lending these sites a layered, sometimes ambiguous character that sets them apart from ordinary graveyards.