But the rest of the circuit survives, rising to two metres at its south-west arc, and beneath the northern edge of the bank something far stranger waits: a souterrain, an underground stone-lined passage system of the kind built across early medieval Ireland, most likely for storage or refuge, whose entrance gap measures just 32 centimetres high. To get in, you would need to go flat.

The rath itself is a univallate ringfort, meaning it has a single enclosing bank rather than the multiple concentric rings associated with higher-status sites. Its internal diameter is 22.8 metres, and it sits on a gentle south-facing slope with Dingle Bay opening out below. Three gaps interrupt the bank; the two at the north-east and south are thought to be later breaches, while the 1.5-metre-wide gap at the north-west is the likely original entrance. The souterrain, documented by J. Cuppage in the 1986 Dingle Peninsula archaeological survey, consists of two passages connected by a low creepway. The first passage runs roughly three metres north to south, its walls built of upright stones capped with drystone masonry and its roof formed by six large slabs. A crawlway in its southern wall, just half a metre square, leads into a second passage that angles south-west and then turns south for at least another metre and a half before the floor fill blocks any further exploration. The maximum headroom in this second chamber is 65 centimetres. The whole system is a tight, deliberate architecture, engineered to be difficult to enter quickly and easy to defend from the inside.