It is a sheepfold, in a sense, but that is the end of a longer story rather than the whole of it. The building began its life as a corbelled drystone hut, a type of dry-laid stone construction in which each successive course of stones projects slightly inward over the one below, eventually closing to a roof without mortar or timber. These structures are known across the Iveragh Peninsula and represent some of the oldest built forms in the Irish landscape, associated variously with early habitation, monastic retreat, and seasonal farming.

The Cahernaman example is oval in plan, measuring roughly 9.3 metres by 5 metres internally, with walls still standing to about 1.8 metres. Its entrance faces south-south-east and is lintelled, meaning a flat stone spans the top of the opening, which is just under a metre high and about the same across, sized for a person to pass through crouching rather than upright. At some point the structure was adapted for use as a sheepfold, a fate common to older stone buildings throughout Kerry where the ready-made enclosure proved too useful to ignore. The adaptation has altered the fabric to some degree, but the corbelled character of the walls and the carefully formed entrance survive to show what the building originally was.