It was absent from both the major national surveys of the late twentieth century, suggesting that whatever happened here was small-scale, inconclusive, and easy to overlook.

What survives, according to the available record, appears to be a post-medieval surface trial for copper. A surface trial is essentially an exploratory scrape or shallow excavation carried out to test whether workable ore lay beneath, before any serious investment in shafts or drainage works was committed. The post-medieval period covers roughly the sixteenth century onwards, a time when interest in Irish mineral resources was growing among English colonial administrators and private speculators alike. Copper was particularly sought after, with deposits elsewhere in Kerry, most famously at Allihies on the Beara Peninsula, eventually proving commercially significant. Here at Rath, though, the trial appears to have gone no further. Whether the ore was too thin, too costly to extract, or simply not followed up is not recorded.