It measures roughly ten metres north to south, eight metres east to west, and rises only about forty-five centimetres above the surrounding ground. That modest profile conceals a long prehistory.

This is what archaeologists call a burnt mound, or fulacht fiadh in Irish, a type of site found in considerable numbers across Ireland and Britain, and dating most commonly to the Bronze Age. The characteristic material, fire-cracked stone mixed with charcoal-rich soil, is the accumulated debris of a repeated process: stones would be heated in a fire and then dropped into a water-filled trough to bring the water to a boil. What the troughs were used for is still debated. Cooking is the most widely accepted explanation, though uses ranging from textile processing to bathing have also been proposed. Over many episodes of use, the cracked and spent stones were discarded into a mound nearby, which is precisely what survives here at Cloustoge. The site sits in agricultural land, and the fact that ploughing has continued around and presumably over it means the mound has likely lost some of its original height, making that forty-five centimetre measurement a minimum rather than a true picture of how it once appeared.