The term megalithic covers a broad family of prehistoric monuments, from portal tombs and passage graves to court cairns and wedge tombs, all sharing the defining characteristic of large stones used in deliberate construction, typically associated with burial, ritual, or the marking of territory and time.

Bolisheen is a quiet townland, and the structure recorded there has not yet been fully documented in publicly available form. What is known is that it was considered significant enough to be formally recorded as a monument, placing it within a tradition of megalith-building that flourished in Ireland roughly between 4000 and 2000 BC. That period saw communities across the island invest extraordinary collective effort in raising stone structures, many of which were oriented with precision toward solar or lunar events, suggesting a sophisticated understanding of the sky and the seasons. Without more specific detail about the Bolisheen example, its exact type, dimensions, and condition remain open questions, but its existence points to a prehistoric presence in this part of Galway that has outlasted almost everything else that came after it.