Its floor is almost entirely covered with set stones, dozens of them packed tightly together, and near the centre a few narrow slabs lie flat across what appear to be complete graves beneath. The effect is dense, purposeful, and unlike most burial grounds in the Irish landscape.

This is a cillín, the Irish term for an unconsecrated burial ground used historically for unbaptised infants, who under Catholic teaching were excluded from burial in consecrated churchyards. Such sites are found across Ireland, often tucked into marginal land, beside boundaries, or near ancient earthworks. The one at Lack is a compact rectangle, roughly fourteen metres north to south and seven metres east to west, enclosed by a low mortared stone wall. It sits about fifty metres west of the Clare River, which itself marks the townland boundary, placing the site at an edge in more than one sense. The small set stones covering the interior would each, most likely, mark an individual child, their modest scale a practical record of just how many burials the ground contains.