At Lisdalleen and Drummin in County Tipperary, an enclosure associated with a nearby castle has left no trace whatsoever on the ground, yet it was clearly visible from the air in GSI aerial photographs taken in 1973. That gap between what the camera once caught and what a visitor would find today is itself the most interesting thing about the place.

Enclosures of this kind typically surrounded or abutted medieval tower houses and castles, serving as defended courtyards or bawn walls, and their outlines can persist in the soil long after the masonry has been robbed out or ploughed away. Crop marks and soil discolouration, the kinds of features that show up on aerial photographs even when nothing remains above the surface, are often the only evidence left. Here, the 1973 photographs recorded just such a pattern, but by the time Jean Farrelly and Caimin O'Brien compiled the Archaeological Inventory of County Tipperary, published in 2002, no surface remains could be identified at all. Decades of agricultural activity can erase earthworks that had survived for centuries, and this site appears to be a casualty of exactly that process.