The graveyard itself is largely rectangular, measuring approximately 44 metres north to south and 60 metres east to west, with a southern portion extending a further 22 metres westward to accommodate the tower. The entrance lies at the south-west, approached from the public road.

The site sits on a natural rise in otherwise gently undulating County Kilkenny terrain, a positioning that would have made practical sense for an early monastic community. That community was almost certainly here by the sixth century: the monastery at Grangefertagh is attributed to St Ciarán of Sir, a figure distinct from the better-known Ciarán of Clonmacnoise, and its origins belong to the same wave of early Irish monasticism that left clusters of ecclesiastical remains across the midlands and south-east. The later medieval church, aligned east to west in the standard liturgical fashion and extended with a north chapel, sits roughly at the centre of the enclosure. The round tower, a type of tall, tapering stone structure associated with early Irish monasteries and understood to have served purposes ranging from bell-ringing to refuge, occupies the westward extension of the southern portion of the graveyard. Stone walls enclose the whole.