Set roughly ten metres apart on the eroding eastern shore of Canon Island in County Clare, they are what remains of a fish weir, a structure designed to trap or net fish as tidal waters moved in and out. A fish weir typically worked by guiding fish into nets or enclosures using a combination of fixed posts, woven hurdles, and strategically placed openings, exploiting the estuary's natural rhythms rather than requiring active fishing effort. Here, given the modest spacing of the two stakes, the more likely explanation is that they once held a net strung between them, rather than forming part of a more elaborate permanent framework.

Radiocarbon dating of one of the alder-wood stakes places the weir in use between approximately 1261 and 1288 AD, a period when Canon Island was home to an Augustinian abbey whose ruins still stand close to where the stakes were found. Alder was a practical choice for stakes driven into wet ground; the wood is notably resistant to decay when kept waterlogged, which is partly why these fragments survived at all. The dating fits neatly into the abbey's working life, and it is reasonable to suppose the weir was connected to the monastic community's needs, though no direct documentary link is recorded here. Two larger timbers were also found lying beside one of the stakes, their relationship to the weir structure unresolved. Whether they are remnants of the same installation or simply later intrusions into the same eroding foreshore, no one has yet determined.