A souterrain is an underground stone-lined passage or chamber, typically associated with early medieval settlement in Ireland, and thought to have served as a place of refuge, storage, or both. What made this particular discovery notable was the survival of the drop-hole, the deliberately narrow opening in the roof through which a person would lower themselves into the chamber below, often designed so that an intruder would be at a disadvantage in the dark. The chamber itself extends northwards from that entry point, though its full extent remains unknown.

The site was investigated by archaeologist Goorik Dehaene under Licence 07E0369, and the findings were eventually published in the excavations.ie record for 2007 as Site No. 1151, with further detail appearing in a 2010 report. Dehaene classified the souterrain as part of Group 7 within the site, a cluster of related features that included a possible kiln, several associated pits, and a linear feature running through the same area. The kiln and pits are thought to reflect activity connected to the souterrain, suggesting this was once a small working landscape rather than an isolated feature. No further excavation of the souterrain itself was carried out, meaning the chamber to the north was identified but left in place.

The proximity to Mungret is the detail that gives this site its deeper context. Mungret was one of the more significant early Christian monasteries in Munster, and the presence of a souterrain so close to its boundary raises questions about the relationship between ecclesiastical centres and the secular settlements that grew up around them. The site at Skehacreggaun is not accessible to the public in the conventional sense, having been identified in advance of development rather than preserved as a visitor destination, and the souterrain itself was left uninvestigated below ground. Those with an interest in the area are better served by visiting the Mungret site nearby, where the ecclesiastical remains offer visible and tangible connections to the same early medieval world that the souterrain briefly illuminated.