The well is known locally as Tobairán an Mhuláin, and the creature living within it is called the Donnánach. According to local tradition, if you ask the fish about an absent loved one, it will swim upside down if that person has died. It is a strikingly direct form of divination, stripped of ceremony, demanding only a question and the willingness to watch.

The well itself is a modest thing physically: a natural oval basin, roughly 0.5 metres by 0.4 metres, set on the western side of a gully near the low water mark on the eastern shore. Holy wells in Ireland were typically sites of healing, pattern days, and votive offering, but the tradition attached to this one is narrower and stranger, concerned not with cure but with knowledge, specifically the knowledge that grief most dreads to confirm. The Donnánach occupies an odd place in that wider landscape of sacred water, functioning less like a saint's well and more like an oracle tied to the tidal margin between land and sea.

Finding it requires a degree of correction. The location marked on the Ordnance Survey six-inch maps is wrong; the actual well sits approximately 80 metres to the south of the indicated point, on the foreshore itself. Anyone hoping to locate it should bear that discrepancy in mind and time their visit around low tide, when the basin is accessible. The gully setting means it is easy to pass over without recognising what it is.