The site measures 56 metres from east to west and 48 metres from north to south, enclosed by substantial earthen banks that would have once provided both defence and drainage. The northern bank, now topped with a hedge, stands about half a metre high on the inside but rises to 1.2 metres on the exterior, whilst the western bank reaches a metre in height when viewed from outside.

What makes this site particularly interesting is its surviving water defences. Along the western side, a fosse or moat can still be traced, measuring 4 metres across at the top but narrowing to just a metre at its base, though it’s now only 40 centimetres deep. The southern moat is better preserved; here the defensive ditch spans 3 metres at its widest point and plunges to 1.7 metres deep on the inner side, creating a formidable barrier that would have been even more impressive when filled with water. The eastern boundary is marked by a 70-centimetre high scarp, separated from a field bank by a 3.5-metre wide berm.

These moated sites were typically built between the 13th and 14th centuries, often by Anglo-Norman settlers or wealthy Gaelic families who adopted this defensive architectural style. The Roxborough example, with its well-preserved banks and ditches, offers a glimpse into medieval rural life in Roscommon, when such fortified homesteads dotted the Irish landscape. Modern entrances have been cut through the western side and at the western end of the southern bank, but otherwise the earthworks remain much as they would have appeared to medieval visitors approaching across the surrounding fields.