A cashel is simply a ringfort built from stone rather than earth and timber, the choice of material usually dictated by what lay close to hand. In the limestone-rich terrain of Clare, stone was abundant, and these circular enclosures were once the defended farmsteads of local families, their thick dry-stone walls marking the boundary between the domestic world within and the open countryside beyond.

Ringforts of this kind were built and occupied primarily between roughly the fifth and twelfth centuries, though many remained in use or were adapted long after that period. Thousands survive across Ireland, making them among the most numerous archaeological monuments in the country, yet individual sites are frequently overlooked precisely because they blend so easily into the fields around them. The cashel at Knocknaskeagh belongs to this category of monument that is common in type but specific in place, a fixed point in the landscape that connects the townland to a particular moment in the early medieval agricultural world of Munster.