Wetland platforms of this kind were typically constructed to provide stable footing or working surfaces over boggy ground, and the fact that so many were found concentrated within a single survey area makes Derryville unusual even by Irish standards.

A field survey by Gowen in 1999 documented the range and variety of these structures in some detail. Most were built from a combination of brushwood and roundwood, the latter referring to small-diameter timber used more or less as it came from the tree. In three cases, small anchoring pegs were driven in to hold the structure in place, and two examples showed woven brushwood, a more deliberate technique that suggests careful construction rather than improvised footing. Radiocarbon dating of four platforms produced dates spanning several centuries, from the Late Bronze Age, roughly 792 to 526 BC, through to the Iron Age, around 351 to 120 BC. The people building here, then, were not all contemporaries; the bog was being returned to, used, and perhaps modified across generations. Wood identification at nine of the sites revealed that builders were selecting from whatever grew nearby: alder, ash, birch, hazel, and willow, all species associated with wet or marginal ground, which suggests they were working with materials close at hand rather than importing timber from drier terrain.