It is a sub-rectangular block, roughly a metre wide and just under three-quarters of a metre deep, rising to a height of 1.34 metres, and it sits aligned along a north-north-east to south-south-west axis. That orientation is not accidental. Many standing stones across Cork and the wider Irish landscape share deliberate alignments, whether towards solar events, prominent hilltops, or other monuments now lost, and this one is no exception in that respect, even if its specific purpose remains unrecorded.

Standing stones of this kind are among the most enigmatic monuments left scattered across the Irish countryside. They date most commonly to the Bronze Age, roughly 2500 to 500 BC, though some may be earlier or later, and their functions are thought to have ranged from territorial markers to ritual focal points to components of astronomical sighting lines. West Cork has a notable concentration of them, sometimes appearing alone in fields like this one, sometimes in pairs or grouped with stone circles and boulder burials. The stone at Rathruane Beg sits quietly within that tradition, its modest dimensions belying the effort it would once have taken to quarry, transport, and erect it on a deliberately chosen hillside.