They are not. Originally laid flat as recumbent slabs, a common early Christian funerary practice, they were repurposed at some point as upright burial markers, which is why most of them cluster in the southern section of the graveyard, where eighteenth and nineteenth-century interments are concentrated. The problem with standing a recumbent slab on its end is that a good portion of it disappears below ground, and so the incised crosses and other features that once lay fully visible across their faces are now largely hidden, cut off by soil and later masonry.

Most of the slabs are of schist, a locally common metamorphic stone that splits into workable sheets, though four of the twenty, recorded as cross-slabs 2, 11, 15 and 16, are of granite. The smallest and perhaps most affecting of the group is cross-slab 1, which sits at the northern end of the eastern gable of Aghowle Church. It is a modest thing, just 27 centimetres wide at the base, 29 centimetres high, and 5 centimetres thick. On its west face is a simple incised cross, the kind cut freehand into the stone rather than carved in relief, and it is incomplete: the top corner of the slab has broken away, taking part of the design with it. Enough survives to estimate that the cross originally measured around 22 centimetres high and 13.5 centimetres wide. There is something quietly affecting about a stone this small carrying a mark that was presumably meant to endure.

Visitors to Aghowle should be prepared for the fact that much of what makes these slabs significant is effectively invisible. Because so many are planted upright in the ground, reading them requires patience and a willingness to crouch and look carefully at what remains above the surface. The graveyard is the place to begin, and the eastern gable of the church is where cross-slab 1 can be found, close against the stonework of the wall.