The rectangular enclosure, measuring 35 metres northwest to southeast and 27 metres northeast to southwest, would have once protected a timber hall or stone building, though no traces of structures remain today. The site is defined by substantial earthen banks that rise up to 1.85 metres on the exterior, creating formidable defensive walls that are between 5 and 8 metres wide. These grass and fern-covered ramparts have weathered centuries but still clearly mark out the protected space within.

The defensive architecture becomes even more impressive when you consider the moats that surround the banks. These flat-bottomed ditches, varying between 6 and 9 metres wide at the top and narrowing to about 3 to 4 metres at the base, would have been filled with water or left dry depending on the local water table and defensive needs. With an external depth of around 2 metres, they would have presented a significant obstacle to any would-be attackers. Beyond the moats, an additional earthen bank encircles the entire complex, adding another layer of defence; these outer banks stand between 0.8 and 1.4 metres high and measure roughly 6 metres in width.

Such moated sites are characteristic of Anglo-Norman settlement patterns in medieval Ireland, typically dating from the 13th to 14th centuries. They served as fortified farmsteads for colonists who needed protection in what was often hostile territory. The substantial nature of the earthworks at Cools suggests this was an important local stronghold, possibly home to a prosperous farming family or minor nobility who could afford such elaborate defences. Today, though overgrown and peaceful, the site remains an evocative reminder of a time when the Irish countryside was dotted with these small fortifications, each one a symbol of the complex cultural and political landscape of medieval Ireland.