Though considerably ruined, the structure consists of four standing stones (orthostats) and what appears to be a displaced roof stone measuring 2.2 metres square and 0.4 metres thick. The massive roofstone currently leans against the western face of one of the orthostats, whilst the other stones remain in their original positions, though their arrangement makes it difficult to determine the tomb’s original design. Given its proximity to the nearby cruciform passage tomb and another probable passage tomb in the immediate area, archaeologists suspect this too may have been a passage tomb. Local records indicate that a large quantity of human bone was discovered here during excavations in 1839.

The site forms part of the larger Kilmonaster Passage Tomb cemetery, a significant archaeological complex that has attracted scholarly attention for decades. The main passage tomb, known as Site A, lies just 140 metres away, whilst Site B, another probable passage tomb, sits nearby. This clustering of megalithic monuments suggests the area held particular significance for Neolithic communities, likely serving as an important ritual or burial landscape over several generations.

Archaeological testing carried out in 2005 ahead of agricultural development work revealed little of archaeological significance in the immediate vicinity, though a single worked flint was recovered from the topsoil; not surprising given the density of prehistoric activity in the area. The site was first documented in detail by antiquarian Fagan in the 1840s and has since been included in numerous archaeological surveys, including the comprehensive Survey of the Megalithic Tombs of Ireland. Despite its ruined state, the monument remains an important piece of the puzzle in understanding the Neolithic landscape of County Donegal, offering insights into the burial practices and monumental architecture of Ireland’s earliest farming communities.