But the graveyard contains layers of ecclesiastical time that have little to do with the 1881 structure at its centre. Somewhere beneath or around the present building lies the footprint of a medieval parish church whose exact position is no longer recoverable, and standing among the graves is a cross-slab, roughly a metre tall, carved with a latin cross in relief on one face. Beside the church, and brought here from elsewhere entirely, sits a sandstone baptismal font that originally belonged to a different parish altogether.

The parish of Siddan, dedicated to Saints Mary and David, was drawn into the orbit of St Mary's Cistercian abbey in Dublin around 1200, when the church was granted to that institution. The Cistercians retained it for the better part of three and a half centuries; it was still listed among the abbey's possessions when Henry VIII's Dissolution of the monasteries reached Ireland in 1540. By the early seventeenth century the building was already in decay. The archbishop James Ussher, writing in 1622, described both the church and its chancel as ruins. Dopping's Visitation of 1682 to 1685, a Church of Ireland survey of parishes in the diocese, recorded that the church had been in ruins since 1641 and was not even enclosed. A replacement was eventually built in 1753, according to Samuel Lewis's account from 1837, and the present St David's followed in 1881. The font now propped outside the church door is a further displacement: it came from Drumcondrath, another Meath parish, and is a carefully made rectangular sandstone basin with chamfered corners and holes around the rim that once held a cover.