Look more closely, though, and it reveals itself as a baptismal font of considerable age and some peculiarity: rectangular rather than the more familiar circular or octagonal form, and notably substantial, measuring 1.2 metres in length, 0.95 metres in width, and 0.6 metres in depth. A font, for those unfamiliar with the term, is a basin used to hold water for the Christian rite of baptism. This one has an unusual asymmetry to it, with one face dressed smooth and the other left deliberately rough, and a channel cut inside the rim that would have directed water within the basin.

The font sits in the grounds of St. John's Anglican church in Clondalkin, a village on the western edge of Dublin that retains traces of a much older ecclesiastical settlement, most visibly in the form of a well-preserved round tower nearby. The stone itself was recorded by F. Elrington Ball in 1899, which places it in the scholarly literature at the very end of the nineteenth century, though the font itself is considerably older. Its rectangular granite construction and the contrast between its dressed northern face and irregular southern face suggest a piece that was shaped with practical intent rather than purely decorative ambition. The channel inside the rim is a functional detail, designed to manage water flow during use.

The font is accessible within the churchyard at St. John's, Clondalkin, and can be found to the south of the church building. It is modest in setting and easy to overlook, particularly for anyone who visits the area specifically to see the round tower and moves on quickly. Those with an interest in early ecclesiastical stonework, or simply in objects that carry the wear of centuries without announcement, will find it worth a few minutes of attention. A three-dimensional digital model of the font has been made available online at skfb.ly/oJ9GD, which allows for a closer examination of the surface textures and the channel detail than a churchyard visit might always permit.