What makes Ballyduagh unusual is not dramatic ruin but near-total erasure, a community that vanished so thoroughly into the land that it took aerial photography in the 1960s to confirm it had ever been there at all.

Cambridge University first identified the site from aerial photographs taken in August 1963 and again in July 1966, and a field survey by Cahill in 1975 confirmed what the images suggested. By 1982, Cahill was describing extensive remains of a deserted village identified by both air photography and field inspection. Mitchell, writing in 1986, was more evocative, noting that the aerial record showed the outlines of houses with gardens at the top of a village street. It is a remarkably complete picture of a community in negative. The site sits almost equidistant between a medieval church and graveyard to the north-west, a 16th or 17th century house and enclosure to the south-west, and a moated site to the south-east; a moated site being a type of medieval enclosed homestead, typically surrounded by a water-filled ditch, associated with Anglo-Norman settlement in Ireland. That clustering of features suggests a landscape that was once densely and purposefully organised. By 1931, however, Simington recorded Ballyduagh as containing little more than a thatched house, some cabins, and a park of ash trees covering two plantation acres. By 1996, when aerial photographer Leo Swan revisited the site, intensive land improvement had reduced even the subtle earthwork evidence to almost nothing, the irregular undulations in the pasture offering no discernible pattern to the eye on the ground.