Known colloquially as ‘Catsby’, this cave contains two mysterious basins carved directly into the bedrock; one measures just 5cm deep with a 10cm diameter, whilst the larger basin reaches 25cm in depth and spans 30cm across. These curious hollows, smoothed by time and perhaps human hands, sit alongside a flat rock projection that stretches two metres long and half a metre wide, which locals have long referred to as an ‘altar’.

The site’s proximity to the ruins of Assaroe Abbey has fostered enduring folklore connections between the two locations. Founded in the 12th century by Cistercian monks, the abbey once stood as a significant religious centre in northwest Ireland before its dissolution in the 16th century. Whether the cave served as a hermit’s retreat for contemplative monks, a place of pre-Christian worship later absorbed into Christian tradition, or held some other ritual significance remains a matter of speculation amongst historians and archaeologists.

These rock-cut basins, known as bullauns in Irish archaeology, appear throughout the country and often carry associations with healing waters, cursing stones, or baptismal rites. The Catsby cavern examples are particularly intriguing given their sheltered location within a natural cave rather than the more common open-air settings. Whilst their exact purpose may never be fully understood, they stand as tangible links to the spiritual practices of Ireland’s past, whether pagan, Christian, or perhaps a blend of both traditions that characterised much of medieval Irish religious life.