Easy to overlook, and quite unlike anything most visitors expect to find there, these levelled terraces are the physical remnants of charcoal production, an industrial process that once shaped the woodland landscape of County Wicklow far more dramatically than is generally appreciated.

There are, by recorded counts, around 75 such platforms on the northern and southern sides of the Upper Lake and to the west and south-west of Reefert Church, with a further 40 similar examples noted separately. Each measures roughly 9 metres by 6 metres and they are distributed at irregular intervals across the terrain. These are charcoal hearths, sometimes called pitsteads or hearth platforms, where stacked wood was covered with earth or turf and burned slowly over several days to drive off moisture and volatile compounds, leaving behind the dense carbon material required by iron-smelting and metalworking industries. The slight levelling of the ground was necessary to keep the carefully constructed wood pile stable during the long burn. The references to these platforms date to observations made in 1940 and recorded again in a 1972 study, suggesting their presence has been known to researchers for some decades, though they remain largely invisible to the general public walking the valley's well-worn trails.

Reefert Church itself is a small Romanesque ruin within the Glendalough monastic complex, and the density of platforms in its immediate surroundings raises quiet questions about the relationship between the monastic community and the industrial use of the surrounding oak woodland over the centuries. The sheer number of platforms points to an operation of some scale, one that would have consumed considerable quantities of timber and left its mark on the valley's ecology long before any formal conservation interest in the area took hold.