The stone circle at Grange, the largest in Ireland, comprises a ring of continuous uprights up to 2.8m high, with a diameter of 45m and backed by an earthen bank 9m wide and about 1.2m tall. The entrance on the eastern side is paved and flanked by uprights. Clay has been packed down to a depth of 60 cm across the whole area of the enclosure.
On excavation it was found to be littered with late Neolithic Beaker pottery. Its near perfect shape and the discovery of a posthole in the very centre of the enclosure, indicates that the circle was measured out from a central stake with a rope. Twelve large orthostats have been placed at intervals around the stone ring, each standing directly opposite one of the other ‘axial’ stones. The stones are contiguous rather than free-standing, and the surrounding bank makes it look more like a form of henge monument than a conventional stone circle. This embankment and the precise arrangement of orthostats suggest that this site had a ritual purpose.
It is the largest standing stone circle in Ireland, 150 feet in diameter and enclosed by 113 standing stones. The largest stone is Rannach Chruim Duibh (Crom Dubh’s Division) and is over 13 feet high and weighs 40 tons. The entrance stones are matched by a pair of equally impressive slabs on the southwest side, whose tops slope down towards each other to form a v-shape.
A short distance to the north-north east of the main stone circle, is a second smaller circle, also constructed of large stones. To the north of this is a large leaning standing stone.