These are the physical traces of charcoal production, an industry that left its mark quietly and systematically across the landscape. Charcoal-making platforms, sometimes called hearths or pitsteads, were created by levelling a section of hillside to provide a stable, roughly horizontal surface on which timber could be carefully stacked, covered with turf or earth, and slowly burned with limited oxygen. The resulting charcoal was a high-temperature fuel essential for iron smelting and metalworking.

At least 75 of these platforms have been recorded at irregular intervals along the northern and southern sides of the Upper Lake at Glendalough, as well as to the west and south-west of Reefert Church, one of the cluster of early medieval stone churches for which this valley is named. A further 40 similar platforms were noted separately by researchers, suggesting the operation was substantial rather than incidental. The references that document them date to 1940 and 1972, meaning awareness of the site is long-standing in the archaeological literature, even if it remains little discussed in the popular accounts of Glendalough that tend to focus almost entirely on the ecclesiastical monuments. The proximity of the platforms to the Upper Lake and to Reefert Church places them in one of the quieter reaches of the valley, away from the main visitor trail that leads through the gateway tower and cathedral.