What remains visible is enough to identify it as a baptismal font, the kind of carved stone vessel used in early Christian and medieval churches to hold water for the rite of baptism, though its precise age is not recorded. The tension between the ancient object and its later architectural context is the quiet oddity here: something old has been absorbed into something newer, and nobody has thought it worth separating the two.

The font is bowl-shaped, cut from a single block of granite measuring roughly 72 centimetres across and 40 centimetres high. At its top sits a circular basin with a flat rim, tapering inward as it deepens, and at the base of that basin a drain hole runs through the stone, narrowing from about eight millimetres wide at the top to just two millimetres at the base. On one side of the font there is a bulbous protrusion, a low rounded ridge of stone projecting outward near the top. What purpose it served, decorative or functional, is unclear, and whatever its counterpart on the opposite side might have looked like remains unknown because that face is now built into the altar.