This is a ring barrow, a type of prehistoric burial monument in which a low earthen bank or mound, sometimes accompanied by a ditch, encloses a central area that may once have held human remains or ritual deposits. The example at Doonaltan is much degraded, but its essential geometry survives: a roughly circular area about 9.4 metres in diameter, with a slightly raised rim around a metre wide that may represent the remains of a levelled bank. The interior is saucer-shaped in profile, dipping gently inward rather than rising to a peak, which is characteristic of this particular monument type.

What makes the Doonaltan barrow quietly interesting is not any single dramatic feature but rather its position and its relationship to the surrounding landscape. It sits at the break of slope, where the ground begins to steepen noticeably, and the asymmetry of its surviving height tells that story in numbers: the south-west side stands only about 0.6 metres above the surrounding ground, while the north-east side, holding its ground against the slope, rises to around 1.4 metres. Nineteen metres to the north-east lies a larger enclosure, a separate but presumably related monument, suggesting that this corner of the Sligo countryside once held some significance for the people who shaped it. Ring barrows of this kind are generally associated with the Bronze Age, a broad period spanning roughly 2500 to 500 BC, though dating any individual example with confidence requires excavation that has not, as far as the available record indicates, taken place here.