Karst is the term for limestone landscape shaped by centuries of water dissolving the rock, leaving behind a porous, fractured terrain prone to springs, sinkholes, and underground drainage. That geological character makes this corner of Mayo naturally spring-rich, and it is out of one such fissure at the plateau's base that this particular well emerges.

The site sits to the north of two further recorded wells in the same townland, which suggests a clustering of venerated water sources in a relatively small area, something not unusual in a region where geology and folk tradition have long overlapped. The well at Killour appears in a survey of Ballinrobe and its surrounding district compiled by D. Lavelle in 1994, which documented archaeological and historical features across the Lough Mask and Lough Carra area. The description is spare, noting only the pastoral setting and the active spring, but the designation as a holy well implies a history of local significance that the landscape itself gives little away about now.