At Drumhart in County Cavan, however, that faint kink at the south-west corner of a hedgerow is just about all that remains to mark a site that Ordnance Survey mapmakers in both 1836 and 1876 thought significant enough to label simply as "Fort". The ringfort, or rath, that once stood here has been levelled entirely, leaving no earthwork, no bank, no visible trace at ground level beyond that one slight deviation in the field's edge.

Ringforts are among the most numerous monument types in Ireland, with tens of thousands recorded across the country. They functioned primarily as enclosed farmsteads during the early medieval period, roughly the fifth to twelfth centuries, defined by one or more circular earthen banks and ditches surrounding a domestic settlement. The Drumhart example occupied the southern end of a high drumlin ridge, the kind of elevated, oval-shaped hill formed by glacial drift that gives County Cavan much of its rumpled, lake-scattered character. That position would have been deliberate: a rath on rising ground offered clear sightlines and a degree of natural defence. By the time the first Ordnance Survey teams passed through in the 1830s the structure was evidently still recognisable enough to record, but at some point between then and now the banks were cleared, most likely in the course of agricultural improvement.