The bank is modest, no more than a metre wide and roughly twenty to thirty centimetres high, curving around the north-western side of a D-shaped platform measuring about three and a half metres across. The reason for that flat edge on the south-east is not architectural but geological: the peninsula drops away there in an almost vertical scarp, and the second half of the original circle has simply gone, claimed by erosion at the very tip of the land.

Bartragh Island sits in the estuary of the River Moy, on the County Mayo coast, and this particular spit projects from the island's western side into the tidal waters. Hut sites of this kind, low earthen or stone foundations marking the footprint of a small round or oval structure, are found across Ireland and can date from prehistory through to the early medieval period, though without excavation it is rarely possible to assign a precise date. What is suggestive here is the slight hollow that survives just outside the arc of bank, consistent with material having been scooped or piled inward to define a sheltered interior. Eleven metres to the north-west, there is a second possible hut site, which raises the quiet possibility that this exposed peninsula tip once accommodated more than a solitary occupant.