It was swallowed by quarrying activity on the north-facing slope of Feltrim Hill in County Dublin, leaving behind only the documentary traces of what had been, by local account, an exceptionally powerful holy well. Holy wells are springs or water sources associated with saints or sacred figures, often visited for their supposed curative properties, and Ireland has thousands of them. This one, however, seems to have occupied a particular rank in the local imagination.

The 1837 edition of the Ordnance Survey six-inch map annotates the site as 'Lady Well', placing it clearly on the northern slope of Feltrim Hill. By 1958, folklorist Caoimhín Ó Danachair recorded that quarrying had already removed it from the landscape. The folklore gathered around it, however, had been preserved somewhat earlier through the Irish Schools' Collection of the 1930s, in which pupils recorded the oral knowledge of older people in their communities. A child from Kinsealy School noted that the well stood in a field behind an iron gate on the road toward Swords, that it was dedicated to Our Lady, and that it served ordinary household purposes as well as sacred ones. The account went further, claiming that two priests had been cured there, one of diabetes and one of cancer, and drawing a pointed comparison with the well at nearby St Doulagh's, which was said to cure only sore eyes. Feltrim's well, by contrast, would cure any disease. A separate account from Swords School named it St Brigid's Well rather than Lady Well, and credited it more modestly with a cure for sore eyes. The two attributions sit uneasily beside each other, which is not unusual for sites of this kind; dedications shifted over time, and local memory was rarely uniform.

There is nothing to visit at the site today. The quarrying that removed the well has long since altered the hillside, and no physical trace has been recorded as surviving. What remains is accessible only through the Schools' Collection entries, which can be read in full on the Dúchas digital archive at duchas.ie. For anyone interested in the landscape itself, Feltrim Hill is a low drumlin north of Dublin, unremarkable to the eye now, though the 1837 map offers a reminder of what the slope once held.