Sometime between the first Ordnance Survey mapping of this site in 1838 and an on-the-ground inspection in June 1973, a northeast-to-southwest running field boundary was driven straight through this early medieval enclosure on the summit of a ridge in Tawnagh, County Galway, cutting it in two and leaving only the northwestern portion with any real presence above ground.

A rath is an earthen ringfort, the kind of enclosed homestead that was built across Ireland during the early medieval period, typically between the fifth and twelfth centuries, and used as a defended farmstead by a family and their livestock. This one sat on the crest of a ridge running northeast to southwest through an area of mixed grassland and tillage. Both the 1838 and 1922 editions of the Ordnance Survey six-inch map recorded it as a circular enclosure, roughly oval in its actual form, measuring approximately 31 metres along its northeast-to-southwest axis. By the time someone walked the ground in 1973, only the section to the northwest of the field boundary had survived with any definition, marked by a low bank of earth and stone. Aerial imagery taken since then suggests that remnant section is still there, though it has been overtaken by trees and scrub, which both obscure it and, in a way, preserve it from further disturbance.

What remains is the kind of site that rewards patience and a good eye more than it rewards casual inspection. The tree and bush cover that has colonised the surviving bank makes the earthwork easier to read in certain lights and seasons, particularly in late autumn or early spring when leaf cover is thin, and the low bank casts enough of a shadow to reveal its line against the surrounding ground.