That continued use is what sets this site apart. Most mass-rocks, the improvised outdoor altars used by Irish Catholics during the Penal era when public worship was prohibited, survive as purely historical curiosities. This one, in the townland of Carker Middle in north Cork, remains an active, if occasional, place of worship, with Mass celebrated on the last Monday in July each year according to local tradition.

The main rock measures roughly 2.1 metres by 1.55 metres and stands about 1.4 metres high, its flat surface serving as a natural altar. A lower slab to the south and two smaller stones filling the gap on the eastern side complete a rough enclosure, a simple arrangement that would have allowed a priest to stand behind the altar stone while a congregation gathered on the slope. The rocks are conglomerate, a sedimentary stone formed from compressed fragments of older rock, common in this part of the Ballyhouras. Somewhere between the mass-rock and a river roughly 60 metres to the west, local tradition holds that a pauper's grave lies marked by stones, though the ground in that direction is now heavily overgrown and the precise location is difficult to determine.

The site is signposted from the road and reached by a forest track, so it is not difficult to find. The surrounding plantation forest means the light is low and the atmosphere somewhat enclosed. Visitors attending the July Mass would find the site in its most active and communally meaningful context, though the overgrown area to the west, where the unmarked grave is said to lie, is worth bearing in mind as a reminder that this landscape holds more than the altar stone alone.