That last detail is the quietly unusual part. Souterrains, the stone-lined underground passages and chambers built during the early medieval period, are typically arranged as a linked sequence, one passage feeding into the next, their layout thought to serve purposes of storage, refuge, or concealment. Here, the three chambers stand apart from one another, which makes straightforward interpretation difficult, particularly given that portions of the structure have collapsed.

The souterrain sits within a ringfort, the circular enclosures defined by earthen banks that were the most common form of rural settlement in early medieval Ireland, dating broadly from the fifth to the twelfth centuries. The chambers themselves are stone-built and roofed with flat lintels laid across the walls. One entrance, positioned near the bank of the fort, opens into a small and narrow chamber. A second entrance in the interior of the fort leads to a more substantial space, recorded at six metres in length and 1.4 metres in height, tall enough to move through with some care but not with ease. The third entrance gives onto a chamber that is now largely infilled with debris and soil. The site was documented by D. Lavelle in an archaeological survey of the Ballinrobe district, published in 1994, which brought together records of monuments around Lough Mask and Lough Carra.