That combination, a defensible elevation with long sightlines across open ground, was precisely the kind of position early medieval farming families sought when they built these enclosures.

A rath, or ringfort, is a roughly circular or oval enclosure defined by one or more earthen banks and ditches, built predominantly during the early medieval period in Ireland, roughly between the fifth and twelfth centuries. They served as farmsteads, the bank offering a degree of protection for livestock and household alike. The Ballindoo example is a broadly oval form, measuring approximately 29.5 metres on its north-north-east to south-south-west axis and around 24.3 metres across. The bank survives best on the western arc, where it still stands to an external height of around 0.65 metres with a width of just over two metres. Elsewhere, time and agricultural activity have taken their toll: an eight-metre section has been removed at the north-west to north, a short semicircular cut interrupts the eastern scarp, and the bank is almost entirely levelled along the south. Two modern field fences now cross the site, one running through the interior and another clipping the southern edge, giving the enclosure the slightly awkward appearance of a place that has been folded into the working landscape around it. A second rath sits roughly 150 metres to the north-east, suggesting that this corner of Mayo once held a cluster of early settlement activity rather than a single isolated farmstead.