This rectangular earthwork measures approximately 39 metres from north to south and 34 metres from east to west, making it a compact but substantial defensive structure. The site is defined by an impressive bank constructed from earth and stone, ranging from 2.5 to 3 metres in width. Whilst the interior height of this bank is relatively modest at 0.2 to 0.5 metres, its exterior face rises dramatically to between 2.2 and 3 metres, creating a formidable barrier for any would-be intruders.

Surrounding the bank is an external fosse, or defensive ditch, which varies in width from 3.6 to 6.2 metres. This water-filled moat would have provided an additional layer of protection for whatever structure once stood within the enclosure. Today, much of the fosse remains wet and marshy, particularly on the northern, southern, and eastern sides; however, the western portion has silted up over the centuries and is now filled with stones and earth that have tumbled from the adjacent bank. A gap in the defences at the northeast corner appears to be a modern intrusion rather than an original entrance.

Time and nature have left their mark on this medieval fortification. The earthen bank is now overgrown with trees and bushes, giving it an almost hidden quality amongst the pastoral landscape. These moated sites, common across Ireland during the Anglo-Norman period, typically housed timber halls or tower houses and served as fortified farmsteads for colonising families. This particular example at Cuilmore stands as a tangible reminder of medieval life in County Galway, when such defensive measures were essential for survival in a contested landscape.