It collects briefly, flows west for a few metres, then turns and runs downslope to the north, as though changing its mind. The spot has the feel of a place that has long been noticed by people, even if the reason why has become harder to read over time.

The well appears by name on the Ordnance Survey six-inch maps of both 1838 and 1929, recorded as Tobercashleen. The Irish form, Tobar Caislín, translates roughly as the well of the little castle, though whether that refers to a nearby feature, a family name, or something else entirely is not clear from the historical record. What is notable is that when it was mentioned in the 1838 Ordnance Survey Letters, the compiler did not describe it as a holy well, simply noting its existence and name in the townland of Mullafarry. Many springs across Ireland carry the prefix tobar and were once sites of veneration, associated with local saints and seasonal patterns of pilgrimage. Whether Tobercashleen ever held that kind of significance, or whether it was always regarded as simply a named local spring, the nineteenth-century sources do not say.