The ringfort itself, known as a univallate rath (a circular earthen enclosure defined by a single bank and ditch), was recorded as a complete circular form on the Ordnance Survey maps of 1841 to 1842. By the time a later survey was made, a road running northwest to southeast had cut across the site, bisecting what had once been a continuous enclosure. The underground structure within it, tucked into the southwest sector close to the inner bank, survived that disruption.

The souterrain, a type of stone-built underground passage or chamber system commonly associated with early medieval raths and used variously for storage, refuge, or ventilation, is constructed entirely of drystone walling, meaning the stones are laid without mortar. It consists of at least two chambers connected by narrow crawl passages called creeps. The first chamber is roughly circular in plan, rising to one and a half metres, and is roofed using the beehive method, where stones are corbelled inward in successive courses until a single large capping slab closes the top. That capping stone measures approximately 0.8 metres across. From this chamber, a creep barely 0.5 metres wide and 0.4 metres high leads for just over half a metre into a second, D-shaped chamber, which rises slightly higher at 1.68 metres. A further creep extends from the southeast side of this second chamber, running roughly east-northeast for 1.62 metres before the passage collapses and becomes impassable. The lintels capping each passage are large flat stones laid across the top, a construction technique consistent with early medieval underground architecture found across Ireland. The detail of the site was documented in C. Toal's North Kerry Archaeological Survey, published in 1995.