Where a typical ringfort, or rath, was thrown up from ditched soil, a cashel was constructed with dry-stone walling, often in areas where stone lay close to the surface and the land made earthworks impractical. Their builders were mostly farming families of middling rank, and thousands of such enclosures survive across Ireland, each one a quiet remnant of a way of life that persisted roughly between the sixth and twelfth centuries.

The Killeenan cashel belongs to a landscape that County Clare holds in unusual abundance. The Burren, which extends across much of the north of the county, is limestone country where the bedrock shoulders through thin soil, and stone construction was the obvious and available choice for anyone marking out a farmstead or enclosure. Cashels in this region tend to survive well precisely because their materials were never as easily robbed out or ploughed away as earthen structures might be. Beyond that broad context, the documentary record for this particular site remains sparse, and the specific history of who built here, and when, has not yet been fully pieced together from surviving sources.