What looks at first like an awkward rise in the rough is actually a rath, the Irish term for a ringfort, a type of enclosed farmstead typically dating to the early medieval period, between roughly the fifth and twelfth centuries. Most were built by farming families of middling status, and tens of thousands of them survive across Ireland, though rarely do they share their ground quite so incongruously with a golf course.

This particular example at Clashanure is the more northerly of two ringforts that sit conjoined, their interiors separated only by a low rise of ground. The site is roughly circular, measuring 32 metres north to south and 30 metres east to west. Its earthen bank still stands impressively, reaching an external height of around 3.5 metres along its better-preserved stretches, though the interior face rises only about half a metre, suggesting considerable silting and settling over the centuries. Beyond the bank lies a fosse, the ditch dug out when the bank was raised, which provided both the material for construction and a further obstacle to anyone approaching the enclosure. The fosse survives around much of the circuit, though along the northern arc it has been heavily overgrown and used as a convenient place to dump stones. An outer bank, standing to about 1.4 metres, remains visible on the western and north-western sides. The interior, which slopes gently down towards the south-east, has been planted with coniferous trees, giving the whole earthwork a somewhat smothered appearance.

For anyone walking the course with an eye on the ground rather than the pin, the sheer bulk of the external bank is the thing to notice. That drop of 3.5 metres on the outside, against only half a metre on the in, speaks to how much the interior has filled over time. The companion ringfort immediately to the south-west shares the same low ridge, and together they represent a pairing unusual enough to suggest that whoever farmed this slope in the early medieval period had a more substantial presence here than a single enclosure alone would imply.