They are not foundations of houses, nor are they natural features of the terrain. They are the remnants of charcoal production, each one a carefully prepared flat surface where timber was stacked, covered with earth and turf, and slowly smouldered over days to produce the dense, heat-efficient fuel that industrial and domestic processes once depended upon. These platforms, known as pitstead or hearth platforms, required level ground to keep the timber pile stable during burning, which is why the hillside around them bears this peculiar pattern of artificial terraces.

The site around Lugduff and the Upper Lake is remarkably extensive. Surveys recorded 75 oval platforms on the northern and southern sides of the Upper Lake and to the west and south-west of Reefert Church, a medieval ecclesiastical site that forms part of the wider Glendalough monastic complex. The platforms measure roughly 9 metres by 6 metres each. A further 40 similarly shaped platforms were noted in separate survey work. Ua Riain documented the site as early as 1940, with Healy returning to it in 1972. At least one possible hut site has been identified in association with the platforms, suggesting that the people working here may have sheltered on site, as the slow burn of a charcoal pile required careful watching over an extended period. The scale of the operation, with well over a hundred platforms spread across the hillside, points to a substantial and sustained industry rather than occasional, opportunistic production.