The structure built around it is stone-built and semi-circular, a modest piece of craft that frames the emerging water rather than containing it, and it sits overgrown with briars now, half-lost in the kind of scrubby terrain that tends to swallow things quietly.

Holy wells are among the most persistent features of the Irish landscape. Typically associated with a local or national saint, they were gathering points for pattern days, the popular religious observances that combined prayer, circumambulation, and communal assembly, often on a saint's feast day. Many were never formally adopted into the liturgical calendar but continued to be visited regardless. The Killour well falls into a cluster of such sites documented in the Ballinrobe district, an area flanked by Lough Mask and Lough Carra in south County Mayo, and surveyed in a 1994 publication compiled by D. Lavelle for the Lough Mask and Lough Carra Tourist Development Association. That survey recorded the well as it was then: stone-built, semi-circular, with a live spring, and already encroached upon by vegetation. The active spring is the detail that matters here, because not every holy well still runs. Many have silted or been drained or simply dried, making a well with a genuinely emergent spring a less common thing than it once was.