That in itself is unusual. Souterrains, the term used for man-made underground passages or chambers typically associated with early medieval settlement, are common enough across Ireland, but it is relatively rare to find two apparently unrelated examples sitting within the same enclosure, separated by only around twenty metres.

The passage recorded here lies in the southern half of the rath, a circular earthwork enclosure of the kind used in early medieval Ireland as a farmstead or defended homestead. An access hole on the inner edge of the south-western bank once led down into a drystone-built passage, its roof formed by large flat lintels laid across the walls. The passage runs north-eastward through the interior of the enclosure for at least seven and a half metres, sloping gently upwards as it goes, before ending at a blockage. The entrance itself is now sealed at ground level. A second, apparently unconnected souterrain passage lies roughly twenty metres to the north-west within the same rath. Whether the two were ever linked, or served separate purposes at different times, is not recorded. What purpose souterrains served is still debated; storage, refuge, and ventilation for associated structures have all been proposed, and it is possible that different examples served different functions at different times.