Overgrown with earth and stone, circular in plan, it measures roughly 14.5 metres across the base and narrows to between 6.7 and 8 metres at the top, rising to about 1.8 metres at its highest northern point. What makes it genuinely odd is what sits at its summit: a conical stone-lined pit, roughly 2.3 metres wide at the top and 1.2 metres deep, tapering inward toward the base. Traces of deliberate facing-stones survive at the south and west. The whole thing has the quality of something carefully made and then quietly forgotten.

A barrow is a burial mound, typically prehistoric, raised over one or more interments and sometimes enclosed with kerb-stones or internal chambers. The pit at the summit here adds an unusual wrinkle; it could represent a later disturbance, or it might be an original feature of the monument's construction. The mound appeared on the Ordnance Survey six-inch map of 1837 without a name, and by the 1914 edition had acquired the label 'Cruckawn', likely derived from the Irish cnoc at n, meaning a small hill or mound. A rath, the earthen ringfort that was the standard enclosed farmstead of early medieval Ireland, sits about 70 metres to the west, suggesting this corner of Roscommon was occupied across several different periods. The Shannon lies only around 150 metres to the north-east, and the ridge position would have made the mound visible across the low ground toward the river.