It is a souterrain, a type of stone-lined subterranean structure built during the early medieval period in Ireland, typically between the seventh and twelfth centuries. These chambers and tunnels were usually constructed by hand, roofed with large capstones, and buried beneath the earth, often in association with a nearby settlement or ringfort. Their exact purpose has long been debated; they may have served as cool storage spaces for food, as places of refuge during raids, or both.

An Gabhlán Beag is a small rural townland in Kerry, a county that contains a considerable concentration of souterrains, many of them associated with the dense scatter of early medieval activity across the Iveragh and Dingle peninsulas. Kerry's geology and its history of small farming communities made it well suited to the construction and preservation of such features. The specific details of this particular example, its dimensions, the number of chambers, its relationship to any surrounding earthworks, and its current condition, remain largely unavailable in accessible public sources at this time.

What can be said with confidence is that the site belongs to a broader tradition of underground architecture that represents one of the more quietly remarkable aspects of early medieval life in Ireland. Hundreds of souterrains survive across the country, many on private farmland, some partially collapsed, others largely intact beneath fields that have been worked for generations without their presence being widely known.