These are charcoal-making platforms, the levelled working surfaces where charcoal burners once stacked and fired timber in slow, smothered heaps, and there are at least seventy-five of them recorded here, each measuring roughly nine metres by six metres.

Charcoal production was a labour-intensive industry that required flat, stable ground on which to build the circular mounds of wood, covered with turf or earth to restrict airflow and allow a long, controlled burn. The platforms found at Glendalough cluster on the northern and southern sides of the Upper Lake and to the west and south-west of Reefert Church, one of the early medieval ecclesiastical structures that give the Sevenchurches area its name. A separate group of around forty similar platforms was also recorded in the vicinity. The industry they represent was likely connected to the ironworking that took place in the valley during the post-medieval period, when demand for charcoal as a smelting fuel was considerable. The references that first drew attention to these features date to 1940 and 1972 respectively, suggesting they were a known but quietly catalogued curiosity for some decades before any wider notice was taken.

The platforms are not marked or interpreted on most visitor trails through Glendalough, which makes them an accidental discovery for anyone who wanders off the more frequented paths near the Upper Lake. Once you know what to look for, the shallow, levelled ovals cut into the slope have a distinct regularity that separates them from natural ground variation.