It is the kind of feature that could easily be dismissed as agricultural debris, but it belongs to a category of monument found right across Ireland and Britain, one of the more intriguing puzzles of prehistoric everyday life.

Burnt mounds are accumulations of fire-cracked stones, typically found beside water, and they date most commonly to the Bronze Age. The accepted interpretation is that stones were heated in a fire and then dropped into a water-filled trough to bring it to the boil, a method sometimes associated with cooking, and possibly with bathing or craft processes that required hot water. The stones crack and blacken with repeated heating and are discarded in a heap, which over time forms the characteristic mound. At Longgraigue, an old stream bed runs adjacent to the site, exactly the kind of water source that would have made the location practical. What makes this particular spot unusual is not that it exists in isolation but rather the opposite: two further burnt mounds lie within roughly eighty metres, one to the south-west and another to the east, suggesting this slight valley was a focus of repeated, perhaps organised, activity over some stretch of time.