They are rainwater chutes, the kind of carved stone channels once fixed to the exterior of a church to throw rainwater clear of the masonry walls, and they are an unusual thing to find pressed into service as funerary monuments.

The largest of these fragments is thought to have come from the original medieval church on the site, recorded under the monument reference DU003-011001-. Rainwater chutes of this type were functional architectural fittings, projecting from the base of a parapet or roof line to prevent water from running down and eroding the stonework below. When a medieval church fell into ruin or was demolished and rebuilt, salvageable cut stone was rarely wasted. Here, rather than being carted away for building material, at least five of these chutes were repurposed within the same churchyard, laid or set as markers at individual graves. It is a modest but telling example of how communities found use for the materials left behind by earlier structures, and how the boundary between architectural fragment and memorial object could, in practice, be quite porous.

Garristown itself is a small village in north County Dublin, and the church and graveyard are located to the southeast of the settlement. The rainwater chute that has attracted particular attention is the largest of the five, and a 3D model of it has been made available online at skfb.ly/oDUWN, which allows for a closer look at its form and carving than a graveyard visit alone might offer. For those going in person, the site repays a slow walk, paying attention not just to the conventional headstones but to the older, plainer stones that do not immediately declare what they are.