The structure is a cashel, a type of ringfort built from dry-stone walling rather than earthen banks, and it measures approximately twenty metres in diameter. Inside, traces of internal subdivisions are still discernible, suggesting the space was organised, perhaps separating sleeping quarters from animal pens, or one household function from another, in the way that early medieval farmsteads across Ireland typically were.

What makes Faunarooska particularly interesting is not the cashel alone but its context. It sits within a multiperiod field system, meaning the boundaries, enclosures, and land divisions surrounding it represent not one moment in time but a layering of human activity across different eras. The cashel itself is most likely early medieval in origin, broadly the period between the fifth and twelfth centuries, when the ringfort was the dominant settlement form across rural Ireland. But the fields around it carry the marks of earlier and later occupation as well, making this plateau something closer to a palimpsest of land use than a single-period site. The structure is visible on aerial photography, including Ordnance Survey ortho imagery from between 2013 and 2018, which is often how such sites are identified and documented in upland areas where ground vegetation can obscure stonework at close range.