To a casual walker they might pass for natural terracing or some forgotten agricultural feature, but they are the physical remains of an industry that once shaped both the woodland and the economy of this part of Wicklow: charcoal production. Charcoal-making platforms, sometimes called hearths or pitsteads, were levelled areas where cordwood was stacked into a conical pile, covered with turf or earth to restrict airflow, and then slowly burned over several days. The resulting charcoal was lighter and more energy-dense than raw timber, making it the preferred fuel for smelting and metalworking before the widespread adoption of coal.

The platforms here number at least 75, positioned at irregular intervals on the northern and southern sides of the Upper Lake and to the west and south-west of Reefert Church, one of Glendalough's lesser-visited monastic ruins. A further cluster of around 40 similar platforms was recorded separately. The scale of the operation is striking. That concentration of platforms in a relatively contained area suggests sustained, organised woodland management rather than casual or opportunistic burning. Ua Riain noted the platforms as early as 1940, and later work by Healy in 1972 confirmed the extent of the site. The proximity to the Upper Lake and to the medieval monastic settlement raises questions about chronology and patronage that the record alone cannot answer, though industrial activity in and around Glendalough is well attested across several periods.