The well, whose Irish name translates roughly as the well of the flies, was once a small pool of clear water in an open field, surrounded by trees hung with rags and votive offerings left by people who had come, sometimes from considerable distances, to seek a cure for sore eyes. Paying rounds at a holy well, a devotional practice involving prescribed circuits of prayer walked around the site, was commonplace at such places across Ireland. What made Tobair na Giolláin distinct was its reputation for self-relocation when its sanctity was violated.

Multiple accounts collected from local schoolchildren in the 1930s as part of a national folklore-gathering scheme tell the same story with minor variations. A woman washed clothes in the well, and the following morning it had vanished from its original position near a hedge or a gate and reappeared some distance away, closer to a nearby ringfort, or lios, a circular earthwork enclosure of early medieval origin. One account names the woman as Mary O'Donnell from Dromerin; another describes the well resettling about four perches from its former spot; a third says it moved to the far end of the field, where it could still be seen at the time of writing. One account notes that the fairy wind was said to travel in the direction of the fort, a detail that places the well's behaviour within a wider landscape of folk belief connecting water sources, ringforts, and the supernatural. By the time researcher Caoimhín Ó Danachair noted the well in 1958, trees still surrounded it; today no surface trace remains.