A souterrain is an underground passage or chamber, typically stone-lined, built during the early medieval period and associated with raths, the circular earthen enclosures that once served as farmsteads across Ireland. This one sat at the centre of just such a rath, its entrance folded into a low earthen bank that ran northwest to southeast through the interior of the enclosure. By the time anyone recorded it properly, it was already blocked. By the time anyone came back to check, the rath itself was largely gone.

When the Galway Archaeological Survey first visited in 1982, the souterrain's entrance measured 3.8 metres wide but only 0.3 metres high, a gap more suggestive of something deliberately sealed than of natural collapse. Two years later, in 1984, the picture had changed entirely. Most of the surrounding rath had been levelled, and a barn had been erected across the western half of what had been its interior. No visible surface trace of the souterrain remained. The speed of that transformation, from a partially legible early medieval site to an agricultural yard, across a single revisit, is the kind of quiet erasure that the archaeological record catches only by accident. A preservation order under the National Monuments Acts, numbered 6/1984, was made that same year, presumably in response to what had already happened rather than before it.