In a field near Tooreen in County Mayo, a circular enclosure roughly 30 metres in diameter once sat on a low rise of ground, with higher terrain pressing in from the south and south-west. Today there is nothing to see at ground level; the enclosure was levelled during land reclamation, leaving no earthwork, no bank, no trace of its former outline.

What we know of it comes from the cartographic record. The Ordnance Survey's six-inch map of 1838 shows a circular enclosure at this spot, and by the 1916 revision it appears as a hachured circle, the conventional symbol surveyors used to indicate a raised or defined earthwork, partially absorbed into the surrounding field boundaries along a south-east to north-west axis. An aerial photograph confirmed its presence before it was lost. Enclosures of this kind are often understood to be related to ringforts, the roughly circular farmstead enclosures that were built across Ireland in their thousands during the early medieval period, defined by an earthen bank and sometimes a fosse, or ditch, around a central living area. Whether this particular enclosure shared that function is uncertain, but its landscape context is suggestive: a ringfort lies 155 metres to the north, and a second enclosure sits just 95 metres to the south, making this a cluster of related monuments that once occupied the same modest ridge in the Mayo countryside.

The site itself offers no visible feature to seek out, but the broader grouping of monuments in this small area of Tooreen speaks to a patch of early medieval landscape that was once considerably more structured than its present pastoral appearance suggests.