They are, in fact, the physical footprint of an industrial process, charcoal production, that once operated at considerable scale in this part of Co. Wicklow. Each platform, roughly nine metres by six metres, was cut and levelled into the hillside to create a flat, stable surface where timber could be stacked into a mound, covered with turf or earth, and burned slowly in low-oxygen conditions to produce charcoal. These constructions are known as hearths or pitsteads, and the regularity of their dimensions, even across irregular terrain, points to a practised and systematic operation rather than occasional woodland burning.

The platforms were recorded in two groups: seventy-five on the northern and southern sides of the Upper Lake and to the west and south-west of Reefert Church, with a further forty of similar form noted separately. Reefert Church is one of the early medieval ecclesiastical structures within the Glendalough monastic complex, which gives the site a layered quality, industrial activity overlapping with, or perhaps drawing on the resources of, a landscape already long occupied and managed. The references to Ua Riain writing in 1940 and to Healy in 1972 suggest the platforms have been known to local historians for generations, though they have never attracted the same attention as the Round Tower or the cathedral ruins nearby.

The platforms are distributed at irregular intervals across the hillside, which means a careful walker on the trails around the Upper Lake may notice the telltale flat cuts in the slope without fully registering what they are. There is no signage marking them as industrial archaeology, so knowing what to look for matters. The slight terrace shape, the consistent oval outline, and the frequency with which they appear once you start counting are the clearest indicators that something deliberate, and repeated many times over, happened here.