It is modest almost to the point of invisibility, a rough subrectangular outline of medium and large boulders, its walls no more than 0.6 to 0.8 metres high. Yet something about its construction catches the eye: the north-west corner thickens to around 1.4 metres, splaying outward in a broad, almost buttress-like slope, as if whoever built it was particularly concerned about keeping that exposed corner together against the weather rolling off the ridge above.

The structure measures roughly 6.5 metres on its longer axis and 5.5 metres across, with a narrow entrance gap of about a metre on the south side. A worked area of bog lies approximately 60 metres to the south, suggesting human activity in the vicinity beyond the building itself. What exactly the building was for remains genuinely uncertain. On the Ordnance Survey six-inch map of 1837, six small rectilinear structures are scattered across this stretch of bog, spaced between 25 and 200 metres apart; by the 1921 edition, none of them appear. That disappearance from the record, combined with the rough construction and the general character of the site, suggests the structures belong somewhere in the post-medieval period rather than deep prehistory. Possibilities include a booley hut, the kind of temporary seasonal shelter used during transhumance when cattle were moved to upland grazing, an animal pen, or a refuge for peat cutters working the bog. Two comparable structures survive roughly 100 metres to the north-east, hinting that this was once a small, informal scatter of seasonal or working buildings across the hillside, all of them now largely reclaimed by the bog vegetation that surrounds them.