A collapsed souterrain, an underground passage or chamber typically cut from stone and used in early medieval Ireland for storage or refuge, lies sunken into the southern interior of a ringfort that has otherwise held its shape for well over a thousand years. It is that combination, an earthwork still largely intact above ground and a hidden subterranean feature now caved in below it, that gives this particular site its quiet strangeness.

The ringfort itself is a rath, the most common type of enclosed settlement in early medieval Ireland, built by encircling a roughly circular living area with one or more earthen banks. Here the enclosure measures 44 metres across in both directions, making it a reasonably substantial example of the form. A single earthen bank, now about a metre high and thick with trees, traces the perimeter. Souterrains are found in association with many ringforts across Ireland, and their exact function is still debated, though most archaeologists favour a combination of cool storage and emergency concealment. This one, in the southern part of the interior, has collapsed, leaving a depression that marks where the structure once ran underground.