This ringfort at Mace in County Westmeath, sitting on low-lying wet pastureland, now describes a D-shape rather than the full circle that cartographers recorded in 1837. A ringfort, sometimes called a rath, is an early medieval enclosed settlement, typically defined by one or more earthen banks and ditches and used as a farmstead. Here, the enclosing bank has been worn down largely to a scarp, a low slope of compacted earth where a proper raised bank once stood, and another ringfort lies just 130 metres to the north-east, suggesting this was once a settled and actively worked corner of the midlands.

The transformation from circle to D-shape is legible in the cartographic record. The 1837 Ordnance Survey six-inch map shows the monument as a complete circular enclosure, but by the revised 1911 edition the south-western quadrant has been cut away by a post-1700 field boundary. That same field fence, running north-west to south-east, along with a drain, now intersects the site at its south-western edge, and to the west of this boundary the monument has disappeared entirely from view. Inside the surviving portion, traces of cultivation ridges run north-east to south-west across the interior, evidence that the ground within the old enclosure was at some point turned over for tillage, which will have further disturbed whatever archaeological deposits remain below the surface.