It is classified as a bowl-barrow, the term for a rounded prehistoric burial mound, typically Bronze Age, enclosed by a ditch and sometimes an outer bank. But the mound at Southhill does not sit entirely comfortably in that category, and the question of what it actually is has never been fully resolved.

The mound itself is flat-topped and steep-sided, measuring roughly nine metres across in one direction and twelve in the other, with a shallow fosse, that is, a surrounding ditch, and an external bank enclosing it. A low causeway crosses the fosse at the southern side. At the north and west, both the bank and fosse have been largely levelled, which makes reading the original form of the monument more difficult. What complicates the classification further is a suggestion made in 1980 that the mound may not be prehistoric at all, but rather the remnant of a small Anglo-Norman motte castle. A motte is an earthen mound, usually steep-sided and flat or slightly domed at the top, which formed the raised platform for a timber or stone tower in the decades following the Norman arrival in Ireland from the late twelfth century. The flat top, the steep profile, and the commanding position on a ridge with extensive views in multiple directions are all features consistent with that interpretation. The road marking the boundary with the neighbouring townland of Mitchelstown runs just twenty metres to the northeast, suggesting the mound has long sat at a point of local significance, whatever its origins.

The uncertainty here is genuinely unresolved rather than a gap waiting to be filled. Without excavation, a mound of this kind can hold its ambiguity almost indefinitely, sitting quietly on a ridge in the Irish midlands while scholars continue to argue about which century built it and why.