Three of them are arranged almost exactly two metres apart from one another, forming an equilateral triangle, a configuration that implies deliberate planning by the people who placed them here. The fourth sits roughly twenty metres to the south-west, now partially absorbed into a field boundary, as though the landscape simply grew up around it over the intervening millennia.

Boulder burials are a monument type found predominantly in south-west Ireland, consisting of one or more large support stones beneath a single massive cover-stone, the whole structure understood to mark a burial. At Derrymihin the cover-stones are substantial slabs: the eastern monument in the triangular group carries a cover-stone measuring 2.2 metres by 1.6 metres, resting on three visible support stones, while the northern monument has a slightly smaller cover-stone of 1.7 metres by 1.3 metres supported by two stones. The western monument in the group is nearly square in plan at 1.5 metres by 1.5 metres, and sits on a single visible support stone. The fourth, fence-bound boulder burial has a cover-stone of 1.9 metres by 1.7 metres, again on two support stones, and is notably the thickest of the group at a metre deep. The site was recorded by Ó Nualláin in 1978, and its triangular arrangement remains one of the more unusual spatial relationships between monuments of this type anywhere in Cork.