An inspection carried out in 1999 found nothing visible at ground level, and yet the site had already yielded a substantial collection of stone tools and pottery, and revealed the outlines of a small settlement tucked into a hollow within a much larger, multi-period field system. The absence of anything to see is, in its own way, part of the point.

The site came to light through the Cahercommaun Archaeological Research Project, when D. Blair Gibson excavated it in 1986 under the designation C-221. Cahercommaun itself is a well-known cashel, a type of stone-walled enclosure associated with early medieval settlement, and the project's broader aim was to understand the cluster of smaller, unenclosed hut sites scattered around it. C-221 turned out to comprise three distinct features. The first, C-221 A, was a roughly rectangular enclosure about six metres long and four metres wide, defined by a collapsed stone wall; this is the feature Gibson concentrated on during excavation. Immediately to the south-west lay C-221 B, a subcircular depression nearly six metres across with a noticeably stone-free interior, and beside it, bedrock cupmarks, shallow hollows pecked into the rock surface whose precise purpose remains a matter of debate among archaeologists. A third feature, C-221 C, was identified as a clochán, a small dry-stone corbelled structure of the kind associated with early Christian and medieval occupation, and was considered later in date than the other two. The excavation of C-221 A linked it to two field systems, possibly constructed at different periods, suggesting the landscape around Cahercommaun was organised and reorganised over a long stretch of time. The artefacts recovered were almost entirely stone tools, which points to prehistoric activity, though the presence of some pottery adds a degree of ambiguity to the chronology.