It is a clochan, a dry-stone beehive hut of a type associated with early Irish monastic and rural life, and it is considered the best preserved example of its kind on the island. Two doorways face each other across the narrow interior, one in the north-west wall and one in the south-east, with a small window cut into the south-west end-wall. The roof is corbelled, meaning each course of stone projects slightly inward over the one below until the courses meet at the top, with no mortar and no timber involved. The whole structure measures roughly six metres on its longer axis and stands to about two and a half metres in height.

The form of a clochan is ancient, and examples elsewhere in the west of Ireland have early medieval origins, but this one is thought to date from the seventeenth or eighteenth century, a much later period than many visitors might assume. That dating comes from the scholar E. Rynne, and it places the building firmly in a post-medieval agricultural context rather than a monastic one. Earlier commentators took an interest in it too: it appears in records by Barry in 1886 and by the prolific antiquarian Thomas Johnson Westropp in 1895, the latter having documented a remarkable range of sites across Connacht during that period. Its location on a terrace above the harbour at Cill Mhuirbhigh, sheltered from the Atlantic winds that shape so much of life on Inis Mór, suggests it served a practical purpose for whoever worked or lived in that part of the island during those centuries.