The cromlech at Fortland is one of the quieter survivors, a portal tomb or dolmen-type structure in which large upright stones once supported a substantial capstone, forming a chamber that served as a collective burial place in the Neolithic period, roughly four to six thousand years ago. The term cromlech, borrowed into Irish usage from Welsh, was the older catch-all word for such structures before modern archaeology settled on more precise classifications.

The principal scholarly record for this monument comes from Seán Ó Nualláin's Survey of the Megalithic Tombs of Ireland, Volume V, covering County Sligo, published by the Stationery Office in Dublin in 1989. Ó Nualláin's survey was a landmark systematic effort to document the surviving megalithic architecture of the country, and the Fortland cromlech appears within its catalogue of Sligo monuments. The Fortland townland name itself is worth a moment's attention: townland names in Ireland frequently preserve older landscape features, and a name suggesting fortification or an enclosure hints at a long human presence in the area, though the cromlech itself predates any medieval or early historic activity by millennia.