This sub-rectangular enclosure sits dramatically on elevated ground, with a steep drop marking its northwestern boundary whilst the southeastern edge slopes more gently down the ridge. Stone walls, now covered in grass, define the northeastern and southwestern boundaries; the former being the more substantial of the two, measuring roughly 1.6 metres wide and standing between 60 and 80 centimetres high. Four narrow gaps punctuate the northeastern wall, with stones still visible in places where the grass covering has worn away, whilst the southwestern wall features a wider opening of about 3.5 metres.

At the heart of this enclosed space sits what archaeologists have identified as a circular hut site, measuring 6.5 metres across its interior. The dwelling's boundaries are marked by another grassed-over stone wall, varying between 1.2 and 1.8 metres in width but rising only about 20 centimetres above the current ground level. A 3.5-metre-wide entrance on the western side would have provided access to this ancient home. The careful construction and strategic positioning of this site suggest it was built by people who understood both the challenges and advantages of their landscape.

This archaeological site forms part of County Donegal's rich tapestry of field antiquities, documented in the comprehensive 1983 Archaeological Survey compiled by Brian Lacey and his team. The survey catalogues the county's archaeological heritage from the Mesolithic period through to the 17th century, providing invaluable insights into thousands of years of human habitation in this corner of Ireland. Sites like this one at Baile Thiarnáin offer tangible connections to our ancestors, who chose these elevated positions for their homes, perhaps for defensive purposes, to avoid the wetlands below, or simply to command the best views across the ancient landscape.