The well at the southern edge of the Gortaghokera house cluster in County Galway is known correctly as Tobar Mac Duach, and what makes it quietly remarkable is the care taken to make it accessible rather than merely preserved. Most holy wells are surface features, marked by a kerb or a niche; this one descends.

The structure itself is modest in its measurements, a triangular enclosure just one and a half metres by one point two metres, built from drystone walling, the traditional technique of stacking stone without mortar that has been used across the west of Ireland for millennia. An entrance at the north-west leads into this small space, and from there the steps continue down to the natural spring below. The dedication to Mac Duach connects the site to Saint Colman Mac Duach, a seventh-century hermit and later bishop associated with the Burren and the broader landscape of south Connacht, a figure whose name attaches to several wells and ecclesiastical sites across this part of the country. The triangular plan is unusual; most enclosures of this type are roughly rectangular or circular, which makes the geometry here worth pausing over.