By 1838, surveyors had recorded it clearly enough: a roughly oval embanked enclosure sitting on a gentle rise in the boggy pasture of Shanvally, measuring around 35 metres across its east-west axis and 30 metres north to south. A rath, to use the Irish term, is an earthen or stone-banked enclosure, typically dating from the early medieval period and associated with farmsteads or minor settlement. This one occupied a modest but deliberate vantage point, with the ground falling away gently for about 120 metres to the banks of the Trimoge River. By the time the 1931 Ordnance Survey edition was published, the rath had vanished from the cartographic record entirely, replaced by the outline of a rectangular field plot that had grown up around it.

The field plot, however, is still there, and so, in a quietly diminished way, is the rath. The western arc of the original bank appears to have been absorbed into the earth and stone field fence that now defines the western boundary of the plot, a wall roughly 1.2 metres wide and standing between 0.8 and 1 metre high. The eastern half survives as a low semicircular undulation curving north to south-west, just perceptible as a rise in the ground. The interior retains a slight slope downward from centre to south. Taken together, these traces allow the original oval to be reconstructed in the mind, even if nothing about the site announces itself as ancient. A trackway once led off northward from the enclosure, visible on the 25-inch map; it too has since been absorbed into the agricultural landscape. A second rath lies approximately 180 metres to the south, suggesting this part of Shanvally was once a more populated corner of early medieval Mayo than its present appearance would suggest.

The site sits within ordinary farmland, and the remains are subtle enough that without some familiarity with the mapped history, the slight earthworks would read as nothing more than uneven ground. The field boundaries that obscured the rath are also the thing that partially preserved it, which gives the place a particular kind of irony worth sitting with.