Most graveyards arrange themselves in simple rectangles, following field boundaries or the logic of a surveyor's line. The one at Killelan, in County Kildare, does something less tidy: it takes a polygonal form, its enclosing wall tracing an irregular, multi-sided outline roughly 41 metres north to south and 57 metres east to west. That shape, together with what sits inside it, suggests a place that accumulated meaning across several centuries rather than being laid out in a single act of planning.

At the centre of the enclosure stands a fortified church, a building type that was once more common in Ireland than it might sound. Fortified churches typically incorporated defensive features, sometimes a tower built to double as a refuge, reflecting the practical insecurities of medieval and early modern rural life. The surrounding wall, though it now dates from after 1700, may well follow the line of something considerably older, since polygonal enclosures of this kind are often interpreted as evidence of an early ecclesiastical site, their irregular outline preserving the curved or angled boundary of a much earlier foundation. To the south-south-west of the church, a medieval graveslab survives, a carved stone marker of the kind used to identify a burial during the medieval period, when such slabs sometimes bore inscriptions, crosses, or effigies of the deceased. The presence of this single slab, positioned slightly apart from the church, gives some sense of how long this ground has been in continuous use.