A cashel is a stone-walled enclosure, typically of early medieval date, used to protect a farmstead or settlement, and the one at Moneygold is unremarkable enough on the surface. What makes this particular site unusual is the small archaeological puzzle lodged within it, one that has shifted category between visits without ever being properly resolved.

In 1991, a fieldworker examining the Moneygold cashel noted three holes in the north-east sector. His first instinct was that they might form a souterrain, an underground stone-lined passage associated with early medieval settlements and used variously for storage, refuge, or ventilation of a dwelling. But alongside that possibility, he observed something else: the soil forming the sides of the holes contained clusters of sea shells, which he identified as probable midden material. A midden is essentially a prehistoric or early historic rubbish deposit, the accumulated domestic waste of a settlement, and shell middens in particular are valuable to archaeologists because they preserve organic material and offer evidence of diet, seasonality, and trade. Shell middens in inland or semi-inland contexts are especially worth noting, since the shells suggest either coastal activity or the transport of seafood some distance from the shore. A later field inspection, however, reinterpreted the three holes not as a souterrain at all but as badger setts, and made no mention of the shells. Whether they were overlooked, deemed insignificant, or simply not visible on the second visit is not recorded.

The result is a small but genuinely open question: shells were seen, noted, and then not followed up. The midden material, if that is what it is, has no formal status in the current record.