Originally these slabs were designed to lie flat over graves, a common early Christian funerary tradition in Ireland. At some point, however, most of them were lifted from the ground and repositioned as headstones, standing upright among the 18th and 19th century monuments that now dominate the southern section of the graveyard. The consequence of this repurposing is a peculiar kind of concealment: stones carved with crosses now have their lower portions buried underground, and the very features that make them remarkable are largely hidden from view.

The majority of the slabs are cut from schist, a locally common metamorphic rock with a characteristic layered texture, though four of the twenty, including the one known as Cross Slab 15, are granite. That particular stone sits in the western part of the graveyard, firmly embedded in the earth so that only its upper section is visible. It measures 24.5 centimetres wide and 8 centimetres thick at the exposed portion, and carries an incised cross on its east-facing surface. The upper transom of the cross is 9 centimetres wide, and the carved lines of the arms extend the full width of the slab. Below the ground, the shaft and the underside of the arms continue unseen, a reminder that what is visible represents only part of the original design.

For anyone visiting Aghowle, the slabs reward a slow and attentive walk through the graveyard rather than a quick glance. Because so many of them are partially buried and clustered among later headstones, they are easy to overlook unless you are specifically looking for the incised crosses. The grouping in the southern section of the graveyard, where the older stones sit alongside more recent monuments, gives a tangible sense of how the site has been used and reused across many centuries.