To a passing eye it would read as nothing at all, perhaps a scorched patch or an old field clearance. What it actually represents is a fulacht fia, one of the most common prehistoric monument types in Ireland, and one that still raises genuine debate about what it was actually for.

A fulacht fia typically consists of a mound of fire-cracked stone, often horseshoe-shaped, surrounding a trough that would once have been lined with timber or stone. The accepted interpretation for much of the twentieth century was that these were ancient cooking sites, where stones heated in a fire were dropped into a water-filled trough to bring it to the boil. More recent scholarship has proposed alternatives, including use as saunas, dyeing vats, or processing sites of various kinds. The site at Rathorgan sits on the northern bank of the Dungourney river, a logical position given that a reliable water source was essential to whatever activity took place here. It survives as a spread of burnt material in tillage ground, measuring approximately ten metres east to west and six metres north to south, its modest dimensions suggesting either partial survival or a site that was never especially large to begin with.