What survives is a cashel, a type of ringfort built from drystone rather than earthen banks, its circular enclosure wall now so thoroughly grassed over that it reads more as a gentle undulation than a deliberate structure. The diameter runs to roughly 39 metres, large enough to have enclosed a farmstead and its outbuildings, though the fabric of the wall is poorly preserved and gives little away to the casual eye.

Cashels of this kind were the standard unit of rural settlement across Ireland for much of the first millennium and into the early medieval period, built by farming families who needed a defensible enclosure for livestock and household. The drystone construction places this example in a broader tradition found particularly across the west of Ireland, where stone was plentiful and earthen banks less practical. What makes this site quietly interesting is its relationship to the wider landscape: another ringfort sits roughly 300 metres to the southwest, suggesting that this part of Bullaun was once a settled, organised environment rather than an isolated holding. Two enclosures within close range of each other imply neighbouring farmsteads, possibly contemporaneous, possibly sequential, working the same low ground from their respective rises.