Cropmarks form when buried features such as walls, ditches, or drains affect the growth of crops above them, producing subtle differences in colour or height that become legible in aerial photographs. In this case, the mark sketches out a modest rectangular structure, roughly ten metres east to west and five metres north to south, just large enough to have been a dwelling, an outbuilding, or some kind of agricultural structure.

What makes its position quietly puzzling is that the building appears to cross a drain feature that once marked the boundary of a wood on Tintern demesne land. That boundary is recorded on both the 1839 and 1925 editions of the Ordnance Survey six-inch map, suggesting the woodland edge was a stable and recognised feature of the landscape across at least a century. The structure either predates that boundary, postdates it, or simply ignored it, and without excavation or documentary evidence, it is impossible to say which. Tintern demesne relates to the land associated with Tintern Abbey in south County Wexford, a Cistercian foundation later converted into a tower house and manor, and the management of its woodlands and boundaries would have been a practical concern for whoever held the estate at any given period. The building itself remains undated, its purpose unrecorded, its occupants entirely unknown.