At Tomnahulla in County Galway, a roughly circular enclosure some 45 metres in diameter was still legible on the third edition of the Ordnance Survey six-inch map, surveyed in 1933, its outline already interrupted by a field wall cutting across its south-eastern and south-western edges. Today, following extensive land reclamation across what was once open, level ground, no visible surface trace remains whatsoever. The enclosure has been absorbed completely into the agricultural landscape.

Enclosures of this kind, typically circular or oval earthworks defined by a bank and ditch, are among the most common archaeological monument types in Ireland and are often associated with early medieval settlement, though they could serve a range of functions from farmstead boundaries to ceremonial use. The 45-metre diameter recorded at Tomnahulla is a modest but not unusual size for a rural enclosure. What makes the Tomnahulla example quietly notable is that a second, similar enclosure lies immediately to its east, suggesting this stretch of north Galway once held a paired or clustered arrangement of some kind. Whether those two enclosures were contemporary, complementary, or entirely unrelated in purpose is now very difficult to say, and with no visible remains surviving above ground, the question is unlikely to be resolved without subsurface investigation.