A souterrain, blocked at its opening, sits just north of a rectangular house site, its interior sealed and its purpose now a matter of inference rather than investigation. Souterrains are dry-stone underground passages or chambers, typically associated with early medieval settlement in Ireland, and commonly thought to have served as places of refuge, cool storage for foodstuffs, or both. That this one survives at all, even in its stopped-up state, is a reminder of how much of the Irish landscape remains quietly layered beneath the visible surface.

The blocked opening was recorded by Donaldson in 1956, noted in relation to the rectangular house site nearby. The association between souterrains and surface settlement is well established in the archaeological record; they were frequently constructed close to, or directly beneath, domestic structures. What the house site at Carhan looked like in use, who lived there, and when the souterrain was sealed are questions the available record does not answer. The site sits within the broader archaeological landscape of the Iveragh Peninsula, a part of Kerry that has yielded a considerable range of early and medieval remains across its rugged terrain.