No date can be attached to it with any confidence. No name is associated with it. It persists as a depression in the ground, roughly nine metres long and five metres wide, quietly outlasting whoever once lived there.

The feature sits within the south-south-western sector of the rath's interior. A rath, also known as a ringfort, is a roughly circular enclosure defined by an earthen bank and ditch, built predominantly during the early medieval period in Ireland as a farmstead or family settlement. The raised rectangular platform within this one measures seventeen metres north to south and fourteen metres across, suggesting a deliberately constructed base rather than a natural undulation. Within that platform, the oval hollow is interpreted as the footprint of an associated structure, most likely a dwelling. The pairing of platform and hollow is a recognisable pattern in early Irish settlement archaeology, where houses were sometimes raised slightly above the surrounding ground level, leaving a readable trace once the walls and roof were long gone. What remains at Barnaderg is the memory of a floor plan, held in the earth.