It was called Sunday's Well, and even in its own era the name prompted confusion. Holy wells, a feature of the Irish landscape for centuries, were typically focal points for localised devotion, often associated with healing, patterns (the traditional festive gatherings held at such sites), and the veneration of a specific saint. But St Sunday, whoever he or she may have been, left no obvious trace in hagiography or local memory beyond this single, now-vanished spring.

The earliest and most vivid record of the well comes from an English writer, Barnaby Rich, who described it in 1610. Rich was not a sympathetic observer. Writing with the particular disdain of a Protestant Englishman towards Catholic Irish practice, he noted that the well was held in 'pretious estimation' by what he called 'the Popish sort of the Irish', who would gather there on Sunday mornings during the summer season in considerable numbers. His sharpest remark, and perhaps his most unintentionally useful one for historians, is that the crowds were so large and so committed to the outing that, had St Sunday himself appeared to deliver a sermon from the New Testament, they would sooner have gone to an alehouse than made the journey to hear him. The jibe was meant to skewer Catholic piety as mere social occasion, but what it actually preserves is a small, lively picture of people moving through the early seventeenth-century city on a warm Sunday morning, heading south beyond the town to gather at a well.

The precise location of Sunday's Well has never been established, and no physical trace of it is known to survive. It belongs to a category of place that exists almost entirely in documentary form, known only through a single hostile mention in a polemical text. For anyone curious about it now, the experience is less about visiting a site and more about reading Rich's account closely, at once a piece of period propaganda and an accidental record of ordinary urban life. The well's exact position on the south side of the city remains unidentified, which means there is no coordinates to follow, no marker to find, and no particular spot to stand and look at. It survives only as a name and a sentence, which is, in its own way, a strange kind of permanence.