But this one is worth a second look. Standing nearly three quarters of a metre tall and approaching a metre in diameter, it is a substantial piece of medieval stonework, with a roughly square basin, rounded corners, and a small drain hole cut into the south-west corner. The east face has taken some damage over the centuries, but enough survives to give a clear sense of what it once was: a baptismal font, the vessel in which a community marked its newest members, now sitting in the grass of Kilmasantan graveyard, also known as St Ann's, at Glassavullaun.

The graveyard also contains the remains of a church, and together these two features point back to a well-documented moment in medieval administration. In 1179, the church and its surrounding lands formed a sub-manor of Tallaght, held within the extensive ecclesiastical estates of the See of Dublin. According to historian William Nolan, writing in 1992, this manor occupied the upper eastern Dodder Valley, a stretch of territory that would have been both agriculturally productive and strategically significant to the medieval archdiocese. The font itself bears a close resemblance to one at St Maelruan's in Tallaght, which is not surprising given the administrative connection between the two sites. Fonts of this type, hewn from a single block of stone and designed to hold water for the rite of baptism, were common features of medieval Irish parish churches, though relatively few survive in such readable condition.

The graveyard sits on the north bank of the Dodder, and the font stands just inside the gate, to the north. It is not a site with visitor facilities or formal interpretation, so some prior orientation is useful. For those who want a closer look before visiting, a three-dimensional model of the font is available online at skfb.ly/oEypG, which gives a good sense of its form and scale. The east face damage is visible in the model, as is the overall solidity of the piece, which has clearly been well enough sheltered by its setting to survive in recognisable shape.