Where a typical ringfort was built up from ditched and banked soil, a cashel was raised in drystone walling, making it a more permanent and materially distinct mark on the landscape. That such a structure survives in this corner of Mayo is a reminder of how densely these enclosures once punctuated the Irish countryside, with tens of thousands built during the early medieval period, roughly the fifth to the twelfth centuries, as farmsteads and places of refuge for farming families and their livestock.

The townland name itself carries some interest. A cartron was a unit of land measurement used in post-medieval Ireland, typically representing a quarter of a quarter-townland, and names of this form often reflect the administrative layering left behind by successive systems of land division. The specific designation Cartronmacmanus suggests an association with a family or individual bearing the surname Mac Manus, though the precise history of how the name attached to this particular parcel of ground is not currently documented in available records. The cashel itself remains one of countless such sites across the west of Ireland that have yet to receive detailed published attention, known to local communities and recorded on maps, but not yet fully studied or described in accessible form.