This is a cashel, a type of ringfort defined by its stone construction rather than the earthen banks more commonly associated with such sites. Roughly 37 metres north to south and 36.5 metres east to west, it is enclosed by a wall about 1.8 metres wide and standing to around a metre in height, levelled somewhat on its north-east side. Patches of rock outcrop are visible within the interior, suggesting the ground here was never entirely tamed.

Ringforts, whether built of earth or stone, are among the most numerous archaeological monument types in Ireland, typically dating from the early medieval period, roughly the fifth to the twelfth centuries, and understood to represent the enclosed farmsteads of farming families across the social spectrum. The stone-walled variety, known as a cashel or caiseal, tends to occur in areas where surface stone was plentiful, making the landscape around Lough Mask and Lough Carra, with their limestone geology, particularly suited to the form. This cashel at Creevaroddaun does not stand alone; another ringfort lies approximately 290 metres to the south-east, suggesting a broader pattern of early settlement activity across this part of Mayo, with multiple enclosed sites occupying the same general terrain.