The enclosure at Carrigmore sits on an east-facing slope near a place called Flemingstown Wood, and its double-bank-and-fosse construction, the classic layout of a rath, a type of enclosed farmstead common in early medieval Ireland, would normally settle the matter. But the presence of mature oak trees at its centre, and the possibility that it served at some point as a tree-ring, a deliberately planted circular grove sometimes used to mark boundaries or sacred ground, means its original purpose remains genuinely open.

The monument measures roughly 28.7 metres north to south and 32.4 metres east to west, enclosed by an inner bank, a fosse (or ditch), and a more substantial outer bank. Ordnance Survey mapping from 1840 already showed it as a circular enclosure with trees inside, and the 1907 edition confirmed the same arrangement, with the site enclosed by a field bank and more trees in the interior. Quarrying has since eaten into the eastern and southern quadrants, removing the outer bank in those areas and, quite possibly, the original entrance as well. No obvious gap survives to indicate where people once passed in or out. At the centre, a slight circular rise of about six metres in diameter hints at some earlier feature beneath the surface, though its nature is unclear. Three mature oaks remain standing where larger trees have been felled, and a faint suggestion of a third, outermost fosse can still be traced in the northwest quadrant, adding another layer of ambiguity to a site that has already been reshaped by centuries of agricultural use.