The difference in height is just ten centimetres above the surrounding surface, and the low bank of earth and stone that traces its outline is only a metre and a half to two and a half metres wide. Easy to walk past, easy to dismiss as a natural undulation, this small rectangular platform measuring roughly 7.4 metres north to south and 5.5 metres east to west is thought to be all that physically remains of a house or hut that once stood within the enclosure.

A rath, sometimes called a ringfort, is one of the most common monument types in the Irish landscape, a roughly circular area enclosed by one or more earthen banks, used primarily during the early medieval period as a farmstead and place of habitation. Finding structural traces inside one is not unusual in principle, but in practice the internal features of raths are often invisible at ground level, having been ploughed out, robbed for stone, or simply flattened by centuries of agriculture and weather. At Doonflin Lower, the slight raised rectangle has survived within the rath recorded as SL018-044001, and while its date cannot be fixed with any precision, its dimensions and position suggest it once formed the footprint of a domestic structure, the walls reduced now to little more than a whisper in the soil.