This ancient monolith stands 1.7 metres tall, with a narrow profile measuring just 40 centimetres wide and 16 centimetres thick, oriented along a north-south axis. The stone's placement offers commanding views across the surrounding countryside, a characteristic that suggests its creators chose this spot with deliberate care.

Standing stones like this one are amongst Ireland's most enigmatic prehistoric monuments, typically dating from the Bronze Age period between 2500 and 500 BCE. Whilst their exact purpose remains a subject of archaeological debate, these monuments likely served multiple functions within ancient communities; as territorial markers, ceremonial sites, or perhaps astronomical alignment points. The Rathmore stone's north-south orientation might have held particular significance for its builders, possibly relating to seasonal observations or ritual practices that have long since faded from memory.

The stone stands in what is now fairly wet pasture land, though the landscape would have looked quite different when it was first erected. Archaeological surveys of County Donegal have documented numerous such monuments scattered across the county, each one a tangible link to the prehistoric peoples who first shaped this landscape. Despite centuries of agricultural activity and changing land use around it, the Rathmore standing stone continues its ancient vigil, a reminder that human history in this corner of Ireland stretches back far beyond written records.