At Derrydonnell Beg in County Galway, an ancient enclosure once marked the landscape, roughly circular and approximately twenty metres across, but nothing of it remains above ground today. Its existence is known entirely because a surveyor in 1838 recorded it on the Ordnance Survey six-inch map, that meticulous early nineteenth-century cartographic project that captured the Irish countryside in extraordinary detail, including features that would not survive the century.

By the time anyone thought to investigate further, a field boundary running east to west had already cut directly across the site, passing from the east-northeast to the west-northwest and effectively erasing whatever physical coherence the enclosure had retained. Circular enclosures of this kind are common across Ireland and typically represent the remains of a ringfort, a type of enclosed farmstead used throughout the early medieval period, though without excavation it is impossible to say with certainty what this one contained or when it was built. What can be said is that it sat roughly 725 metres to the southeast of a second enclosure in the same townland, suggesting a landscape that was once more densely organised and inhabited than its current appearance would suggest. The 1838 map, then, is the only surviving witness, a single notation that now stands in place of the enclosure itself.