They are easy to overlook, and most visitors who pass near Reefert Church or the Upper Lake never register them for what they are: the physical remains of an industrial charcoal-making operation, preserved in the landscape for centuries.

Charcoal was produced by stacking wood into a carefully constructed mound, covering it with earth or turf, and burning it slowly with limited oxygen over several days. The platforms, each roughly nine metres by six metres, were levelled into the hillside to give the woodcutter, or collier, a stable working surface on which to build that mound. At Lugduff, around seventy-five such platforms have been identified at irregular intervals along the northern and southern sides of the Upper Lake and to the west and south-west of Reefert Church, with a further forty similar examples recorded nearby. The consistency in shape and size across so many individual platforms points to a systematic and sustained effort, not occasional or opportunistic burning. Ua Riain noted the site as early as 1940, and Healy returned to it in 1972, by which point the platforms were already understood as a coherent industrial complex rather than a series of unrelated earthworks.

The platforms themselves are subtle features, and knowing what to look for makes the difference between seeing them and walking straight past. The levelled terraces, oval in outline and cut gently into the slope, are the key thing to notice. Their distribution across a considerable stretch of the valley floor and lower hillsides suggests the operation drew on timber from the surrounding woodland over a long period, leaving behind this quiet grid of earthen scars across ground that has otherwise returned to scrub and heath.