It measures roughly one and a half metres in height and just over a metre long, aligned along a northeast to southwest axis, and at some point a second stone of similar dimensions was laid at right angles to it. Whether the two were always associated, or whether the second came to rest there through later agricultural tidying, is not recorded.

Standing stones of this kind appear throughout West Cork and across Ireland more broadly, raised during the Bronze Age or possibly earlier, though their precise purposes remain debated. They may have served as territorial markers, ritual focal points, or elements within larger ceremonial landscapes. This particular example was noted by O'Brien in 1970 and later included in the Archaeological Inventory of County Cork. What makes Derrymihin quietly unusual is less the stone itself than its present condition: incorporated into a working field boundary, it has continued to serve a practical function for farmers long after its original meaning was lost. The alignment northeast to southwest is a feature seen at other prehistoric standing stones in Ireland, sometimes interpreted as an astronomical orientation, though no specific claim of that kind is made for this site.

The stone sits in open pasture, so visibility from the surrounding land is likely good, and the southward outlook toward Bantry Bay gives some sense of why this elevated position may have been chosen in the first place. Visitors to the Beara Peninsula, already well supplied with prehistoric monuments, may find it worth looking for, though the fence incorporation means it requires a careful eye to distinguish monument from field boundary.