The site measures approximately 40 metres from north to south and 30 metres from east to west, though dense vegetation now obscures much of its original features. This type of defensive structure was common in medieval Ireland, particularly during the Anglo-Norman period when settlers needed fortified homesteads to protect their families and livestock.

The site’s defensive characteristics remain well preserved despite centuries of abandonment. A substantial earthen bank encircles the area, with an external fosse, or defensive ditch, running around the perimeter. The fosse measures 3 metres wide at its base and reaches a depth of 1.3 metres, dimensions that would have presented a formidable obstacle to potential attackers. An adjacent stream feeds water into the ditch, a clever bit of medieval engineering that would have kept the moat filled year-round whilst also providing a ready water supply for the inhabitants.

These moated sites served as fortified farmsteads for Anglo-Norman colonists and wealthy Irish families during the 13th and 14th centuries. They represented a middle ground between the grand stone castles of the nobility and the undefended settlements of ordinary farmers. The Spahill example, documented in the Archaeological Inventory of County Carlow published in 1993, offers visitors a glimpse into this turbulent period of Irish history, when the landscape was dotted with such defensive homesteads; each one a small island of security in an often uncertain world.