In a field to the north-west of Carrowroe House in County Galway, a ringfort once occupied a roughly circular area of ground some fifty metres across. A ringfort, in its typical form, was an enclosed farmstead of the early medieval period, defined by one or more earthen banks and ditches and serving as the fortified residence of a farming family. This one left no visible mark on the surface. Walk the grassland today and there is nothing to see, no bank, no depression, no shadow in low winter light that might betray the outline of something older beneath the soil.

The evidence for its existence comes from the first edition of the Ordnance Survey six-inch map, which recorded it as a circular enclosure at a time when at least some trace of it was still legible, either on the ground or through earlier documentary sources available to the surveyors. Those nineteenth-century maps captured a great deal of the Irish archaeological landscape that has since been lost to agriculture, drainage, and the slow levelling of earthworks over generations of ploughing. Approximately eighty metres to the south-south-east, a second earthwork was recorded, suggesting that this corner of north Galway was once a more densely settled patch of early medieval countryside than its current appearance would suggest.