Measuring roughly eight metres by seven, it is defined by grassed-over banks that may be all that survives of a house, though when it was built, by whom, and for how long it was occupied remain open questions.

The enclosure it sits within is a cashel, a type of drystone-walled fort or farmstead found widely across early medieval Ireland, though the term covers a broad chronological range and does not pin a site to any particular century. This particular cashel is rectilinear in plan, which is itself somewhat unusual; the more familiar form tends toward the circular or oval. The possible house occupies its south-east corner, a position that would have offered some shelter from prevailing westerly weather. The oval shape of the feature is consistent with house forms known from early medieval and later periods in Ireland, but without excavation the dating remains genuinely indeterminate. Gleninsheen is already known in archaeological circles as the findspot of a magnificent Bronze Age gold gorget discovered in the nineteenth century, so the landscape around it has clearly accumulated human activity across a very long span of time. This modest grassy oval is a quieter kind of presence in that same landscape, its precise story still unresolved.