What looks at first like a natural undulation in the field is in fact the barely legible remains of a cashel, a ringfort built from drystone walling rather than the earthen banks more commonly associated with early Irish settlement. The wall, now grassed over and eroded, traces a circuit roughly 44 metres in diameter, its original form all but absorbed back into the landscape.

Cashels were typically constructed during the early medieval period, roughly between the fifth and twelfth centuries, serving as enclosed farmsteads for a single family or small community. The drystone technique, stacking uncut or roughly shaped stones without mortar, was particularly common in areas where stone was plentiful and timber less so. At Corbally, so little survives above ground that it takes some effort to read the site at all. The circular cashel is documented in the Archaeological Inventory of County Galway Vol. II, compiled by Olive Alcock, Kathy de hÓra, and Paul Gosling and published in 1999, which describes it simply as very poorly preserved. That spare phrase, in the context of a systematic county survey, speaks to how thoroughly time and agriculture have worked on the site.

What remains is essentially an exercise in looking carefully at ground level. The grassed-over wall creates a low, continuous rise that becomes clearer once you know what you are tracing. Sites like this reward patience over spectacle; the interest lies less in what is visible than in the quiet fact of its survival, however diminished, on an ordinary Galway hillside.