Fitted into a drystone-built, lintelled niche, the kind of small stone recess that frames a source of water and marks it as something more than ordinary, it is easy to pass without a second glance. Yet the site carries two names and a habit of accumulated identity that is quietly interesting: on Ordnance Survey maps it appears as Toberone, an anglicisation of Tobar Eoin, meaning the well of John, while locally it has long been known as Tobar na Rátha.

The question of which name belongs here, and whether both ever referred to different places, occupied several scholars over the course of the twentieth century. An Seabhac, writing in 1939, and the folklorist Caoimhín Ó Danachair, writing in 1960, each treated Tobar na Rátha as a separate well within the same townland of Márthain. But O'Sullivan, as far back as 1931, argued that both names applied to a single well, with Tobar Eoin being the earlier form and Tobar na Rátha a later local usage. The Ordnance Survey mapping, which preserves the older name, appears to support that reading. Ó Danachair also recorded a tradition that a turas was formerly held at the well on the 24th of June. A turas is a devotional circuit, a pattern of prescribed prayers and movements around a sacred site, typically associated with a saint's feast day; in this case, the date aligns with the feast of Saint John the Baptist, which fits neatly with the Tobar Eoin dedication and perhaps helps explain why that earlier name was considered significant enough to map.