At the south-east corner of a rectangular graveyard near Knockeen in County Waterford, a portal tomb, one of those ancient megalithic structures in which two or more upright stones support a large capstone, has been built directly into the boundary wall. That a Neolithic monument should end up serving as a graveyard corner-stone is unusual enough; that the graveyard also contains the ruins of a medieval parish church, already derelict by 1615, adds another layer of quiet strangeness to a site that appears, on the surface, to be a fairly ordinary piece of rural Irish landscape.

The church is the former parish church of Kilburne, recorded as being in ruins as early as 1615 in a survey of the Protestant diocese of Waterford. What survives today is modest: only the north and east walls remain standing, reaching a maximum height of around 2.4 metres, with the trace of a single window light visible in the north wall. The building measures roughly 20 metres east to west and just under 7 metres north to south. Towards the western end, a cross-wall creates a small internal cell, measuring approximately 3 metres by 4.8 metres internally, which the Waterford antiquarian Reverend P. Power identified in 1895 as a tower. A separate cell of drystone walling, that is, walling built without mortar, is attached to the outside of the south wall at the same western end, adding another small compartment to an already complex little structure. The surrounding graveyard itself is a substantial rectangle, approximately 65 metres east to west and 45 metres north to south, oriented on a gentle south-facing slope.