Megalithic tombs are among the oldest human-made structures in the country, built during the Neolithic period, roughly five to six thousand years ago, when communities of early farmers constructed elaborate stone chambers for their dead. They come in several forms, including court tombs, portal tombs, and passage tombs, each with its own architectural logic and regional distribution. Mayo, with its exposed uplands and ancient field systems, is particularly well furnished with such monuments.

Beyond its classification and location, the specific history of this tomb remains difficult to reconstruct in detail. What can be said is that Rathlackan sits in a part of Mayo where the prehistoric landscape has survived with unusual persistence, and where the underlying geology, dominated by limestone and bog, has preserved evidence of early settlement that elsewhere has been lost to development or agriculture. The presence of a megalithic tomb in such a townland is a reminder that the land was understood, organised, and marked by people long before any written record begins.