But St. Finian's Well carries a particular kind of local weight, the sort that accumulates through centuries of attributed cures and cautionary tales told at school desks. A holy well, in the Irish tradition, is a freshwater spring regarded as sacred, often associated with an early Christian saint and visited for healing purposes, sometimes on specific feast days. This one, in the parish of Newcastle, is dedicated to St. Finian, and its modest physical presence, roughly three feet in diameter and two feet in height, gives little away about the stories layered around it.

The most vivid of those stories was recorded in 1937 as part of the Irish Folklore Commission's Schools' Collection, when pupils at Saggart School set down what was then described as an old story going around the village. According to the account, in 1798 English soldiers stationed in Newcastle desecrated the well when one of them washed his feet in it. The well's response, as the story has it, was to flood the entire village and drown the soldiers. The local Catholic curate was called upon to bless the waters, and only then did they slowly recede back into the well. Alongside this dramatic episode, the collected folklore also records curative traditions: one account describes a lame man who carried a bucket of water home from the well, bathed his foot in it repeatedly over three weeks, and recovered fully. The Schools' Collection entry notes that such practices were continuing at the time of recording, for ailments of all kinds.

The well sits within Newcastle Farm, in a parish to the south-west of Dublin city. Because it lies on private or farm land, access may require some local enquiry before visiting. The physical structure itself is unassuming, the concrete coping and granite lintel doing practical work rather than making any grand gesture, so it rewards close attention rather than a passing glance. Photographs taken by folklorist Caoimhín Ó Danachair are held in the National Folklore Collection at UCD and accessible through the Dúchas digital archive, offering a useful sense of the well's appearance and setting before any visit.