The slabs, most of them cut from local schist with a handful in granite, were made to lie flat as grave covers. At some point, probably during the busy burial activity of the eighteenth and nineteenth centuries, they were lifted upright and pressed into service as ordinary headstones. The consequence is that a great deal of their carved surfaces now sits below ground, hidden from view entirely.

Cross-slabs are among the earlier forms of Christian grave-marking in Ireland, typically incised with a simple or elaborately ringed cross on a flat stone that would have lain directly over a burial. At Aghowle, the reuse of these older stones by later generations has created an accidental kind of concealment. One slab, recorded as Cross Slab 9 and standing in the south-east corner of the graveyard, illustrates the problem well. It measures sixty-four centimetres wide and just five centimetres thick, and currently stands only thirty-seven centimetres above ground. On its east face is a cross that appears to form part of a more elaborate decorative scheme, but because the design continues below the present ground surface, the full composition remains impossible to read. What is visible is essentially a fragment of something larger and more considered.

Walking through the southern section of the graveyard, where the cluster of upright slabs sits among the later headstones, it takes a moment to register that some of the older, plainer stones are not quite what they seem. The carvings that do remain visible, even partially, reward close attention, particularly on overcast days when raking light can pick out incised lines that flat midday sun would wash away entirely.