Stand in the pasture on top of the drumlin where it once sat, and you will find nothing: no earthen bank, no trace of a ditch, no subtle ridge in the grass to suggest that anything was ever here. The site is, in practical terms, invisible.

A rath, as ringforts of this type are sometimes called, was typically a circular enclosure defined by an earthen bank and outer ditch, used in early medieval Ireland as a farmstead and place of shelter. Thousands once dotted the Irish countryside, and County Monaghan, with its rolling drumlin landscape, would have had its share. The Annareagh example is recorded on a revision of the Ordnance Survey six-inch map dated 1858, itself an update of the original 1834 survey, where a circular earthwork is clearly depicted on the drumlin summit. At some point between that mapping and the present, the feature was levelled entirely, most likely through agricultural improvement, leaving the cartographic record as the sole evidence that it existed at all. The drumlin itself, one of the low whale-backed ridges of glacial sediment that give this part of Ireland its characteristic lumpy topography, survives; the human mark on its crest does not.