Known locally as Tobar Muire, meaning Mary's Well, it is not the grand stonework of a formally venerated site but something quieter and more makeshift: a natural round basin in the bedrock, with a square cairn built up on its southern side to form a rough canopy over the water. Modern offerings left inside it suggest the place has never entirely slipped out of use.

What gives the well its particular weight is a story recorded by Mac Giollarnáth in 1941, reaching back to the Penal Laws era, when Catholic worship was suppressed across Ireland and priests who continued to minister openly risked arrest or worse. According to that account, mass was celebrated at this spot on the hillside, and on at least one occasion a priest was captured here. The location just above the former tillage boundary is quietly telling: the edge of cultivated land was also the edge of the visible, settled world, a margin where a congregation might gather with some hope of warning before authorities arrived. The cairn canopy over the basin, modest as it is, may itself reflect something of that clandestine tradition, a small shelter shaped from what the hillside offered.

The well sits on the southern slope of Cnoc an Choillín in Connemara, and Tim Robinson's 1985 mapping of the area places it at a specific point above the old cultivation limits. For anyone approaching on foot, that former agricultural boundary, now readable as a change in vegetation or stonework, serves as a rough guide to where the ground levels off into rougher terrain and the well comes into view.