It is not the ruin of a cottage or a field shelter in any ordinary sense. The structure is corbelled, meaning its walls were built by laying flat stones in progressively overlapping courses to close inward and form a roof without mortar or timber, a technique associated with early medieval monastic and hermitic building in Ireland. The hut measures roughly 3.8 metres by 3.3 metres across, stands about 1.4 metres high, and has walls approximately 1.2 metres thick. That combination of dimensions, a low profile with massively thick walls, points to something carefully engineered for permanence rather than temporary use.

The interior holds two details that reward attention. Against the southern wall there is a wall-niche, a small recessed shelf built into the stonework, the kind of feature often used to hold a lamp or a devotional object. A secondary curving wall also bisects the interior, dividing the already compact space into distinct areas, though what purpose this subdivision served remains unclear. The hut sits within the south-west sector of a larger drystone enclosure, roughly 36 metres by 30 metres, which may be broadly contemporary with the hut itself. Drystone enclosures of this type, built without mortar from locally gathered stone, are found at a number of early monastic sites along the Kerry coastline, and Puffin Island, known in Irish as Oileán na gCánóg, has long been associated with early Christian activity in the region, though no precise date has been established for this particular structure.

Access to the island is by boat, and landings depend entirely on sea conditions. The island is a protected seabird colony, and any visit would need to take account of nesting seasons and any relevant landing restrictions in force at the time.