Roughly 10.9 by 9 metres across, the raised platform is all that remains visible of an early hut site, but at its northern edge, half-swallowed by accumulated earth and stone debris, is the entrance to something considerably older and stranger: a souterrain, a narrow underground passage built entirely without mortar, its roof formed by four large stone slabs.

Souterrains, from the French for "underground passage", are drystone-built tunnels associated with early medieval settlement in Ireland, thought to have served variously as storage spaces, refuges, or places of concealment. This particular example, recorded as part of the Corca Dhuibhne archaeological survey published by J. Cuppage in 1986, extends 2.4 metres southward from its entrance. It is just one metre wide and only 0.45 metres high above the debris that now covers the floor, which means that even at its original full height it would have admitted nobody who was not prepared to crawl. The passage sits in a landscape already layered with early human activity; the Brandon mountain range on the Dingle Peninsula carries one of the densest concentrations of archaeological remains in Ireland, from early Christian oratories to field systems worn into the hillside over centuries of use.

The site lies in the townland of Baile na hAbha, and access to the lower mountain slopes is on foot. The entrance to the souterrain is partially obscured by debris, so the raised oval platform of the hut site is the more immediately legible feature on the ground. The four capstones roofing the passage are visible at the northern edge of the platform, and even with the floor filled in, the proportions of the passage give a clear sense of how confined and purposeful a structure this would have been.