Wetland platforms of this kind were built directly into boggy terrain, typically to provide stable footing or working surfaces in areas that would otherwise have been impassable, and the preserving qualities of peat, which excludes the oxygen that drives decay, have kept the timbers in a condition that would be impossible in drier ground.

A field survey of Derryville Bog, carried out and published by Gowen in 1999, recorded these nineteen structures in detail. Most were built from a combination of brushwood and roundwood, the latter being simply unworked timber branches or small trunks. At least three of the platforms incorporated small anchoring pegs to hold the structure in place, and two showed evidence of woven brushwood, suggesting a degree of craft and intention beyond simply laying timber flat. Wood species were identified at nine of the sites, with alder, ash, birch, hazel, and willow all represented; these are exactly the trees one would expect to find growing at the margins of a bog, suggesting builders were working with whatever grew close at hand. Radiocarbon dates were obtained from four platforms, and the results span a considerable stretch of time: one dates to the Late Bronze Age, between 792 and 526 BC, and another to the Iron Age, between 351 and 120 BC. The platforms were not, in other words, the product of a single episode of activity, but reflect generations of people finding the same practical solution to the same wet problem.