The rath at Carrowgallda sits on a slight rise in pasture land in County Mayo, with the Gweestion River running about 440 metres to the north, and two further raths lying 120 metres to the north-west and 230 metres to the north-north-east. Whether this clustering reflects a single extended farmstead, related family groups, or successive phases of settlement is not recorded, but the proximity alone gives the site an unusual quality.

A rath is an enclosed farmstead of the early medieval period, typically defined by one or more earthen banks and ditches surrounding a circular area where a family and their animals would have lived. At Carrowgallda, the raised circular platform measures roughly 28.5 metres across and is defined by an earthen scarp, the remnant bank, which survives to about 1.3 metres on the north-east side but has been worn considerably lower on the south-west. On the southern and south-western arc, a fosse, that is a defensive ditch, roughly three metres wide runs alongside an external bank that still stands over a metre high on its outer face. A gap of about two metres in the bank to the south-south-east is thought to mark the original entrance. The western portion of the monument has been clipped by a modern road, which has removed part of both the fosse and the outer bank. Inside, the level interior contains a low mound of earth and stone near the north-east of centre, most likely a heap of material cleared from the surrounding fields over many generations rather than anything of archaeological significance in itself. A second dump of large field-clearance boulders has been deposited in the fosse on the south-east side, a reminder of how working farmland slowly reshapes the monuments it surrounds.

The perimeter is ringed with hawthorn and hazel, the kind of scrubby boundary planting that often persists around raths long after the earthworks themselves have degraded. The interior is largely overtaken by brambles, which makes close inspection difficult. The enclosing vegetation and the damaged western arc give the site a somewhat dishevelled appearance, but the north-eastern scarp and the surviving stretch of fosse and outer bank still convey a clear sense of the original form.