This is a caher, a type of stone ringfort common to the west of Ireland, built not from earthen banks but from dry stone masonry, with a rubble core faced on both inner and outer surfaces. The one at Keeas is roughly oval, measuring just over twenty-one metres north to south and twenty-two metres east to west, large enough to have sheltered a farmstead and perhaps animals. From inside, the wall rises only about 1.3 metres above the current ground level, suggesting significant accumulation of collapsed stone against the inner face, particularly at the north.

The enclosure retains what appears to be its original entrance, a gap of around 1.1 metres at the south-east, narrow enough to control the movement of people and livestock. A wider gap at the west-north-west, 1.5 metres across, is thought to be a later breach rather than an ancient feature. Tucked against the inner face of the western wall is the outline of a small rectangular hut, measuring just three metres by 1.8 metres internally, with its own entrance facing east. These lean-to stone structures, built into the shelter of the enclosing wall, are a recurring feature of cahers across Munster and give a sense of how tightly domestic life was organised within. Local tradition holds that a souterrain, an underground stone-lined passage used for storage or refuge, lies somewhere beneath the site, though it has not been located or accessed. Just outside, a pile of field clearance material serves as a quiet reminder that this landscape has been worked continuously for a very long time, with the ancient and the agricultural sitting side by side.