A rath, as such earthwork enclosures are commonly known, was typically a circular banked enclosure used as a farmstead during the early medieval period, roughly 500 to 1200 AD, and thousands of them once dotted the Irish countryside. This particular example measured approximately 25 metres in diameter according to the first edition of the Ordnance Survey six-inch map, where it appears as a neat circular outline. Today, nothing of it can be seen at ground level.

The first edition OS six-inch map, surveyed in the 1830s, captured a landscape still legible in ways it no longer is. When the cartographers passed through this part of North Galway, the enclosure at Boughil was sufficiently defined to be recorded and drawn. It sat on a ridge facing south-west, with extensive bogland stretching away to the north, a setting that would have made reasonable sense for an early medieval farming enclosure, positioned above the wet ground rather than within it. At some point between that survey and the present, the surface traces disappeared entirely, lost to agricultural activity, erosion, or the slow levelling that time applies to earthworks built from nothing more durable than piled soil.

What remains is essentially a cartographic ghost, a circle on an old map corresponding to a patch of field that gives nothing away. The bogland to the north endures, and the ridge is still there, but the enclosure itself survives only as a classified record, its location fixed by grid reference rather than by anything you could put your hand on.