Not a field boundary, not a fence post, not a drainage channel, but an unclassified structure of unknown purpose that runs, or rather ran, roughly south-west to north-east across Derryvella bog. What makes it quietly puzzling is the geometry: two sightings identified 21 metres apart on opposing fields, with only three elements surviving, two pegs to the east and one to the west, each driven into the ground at a consistent inclination of 60 degrees. That uniformity of angle suggests this was not accidental deposition but deliberate construction. The whole thing, were it complete, would have stretched approximately 23 metres in length.

The pegs themselves are slender, ranging between two and seven centimetres in diameter, and the single piece of wood identified from the site was hazel, a species with a long history of use in Irish wetland construction, valued for its flexibility and relative durability when kept waterlogged. The peat surrounding the structure is described as poorly humified sphagnum, meaning it has not broken down significantly, with occasional inclusions of heather (calluna) and cotton grass (eriophorum), plants typical of a raised bog environment. Poorly humified peat is significant for preservation: the more intact the organic material, the better the conditions for keeping ancient wood from decaying entirely. Even so, the tops of the eastern pegs had suffered badly from machinery working the field surface, and the western peg, protruding from a drain face, had also taken mechanical damage. What survives is a fragment of something that was already fragmentary when it was recorded.