The only solid record of it is a cartographic one: the Ordnance Survey's six-inch map of 1838 marks a roughly circular embanked enclosure, somewhere between seven and ten metres in diameter, sitting on that low rise. By the time later map editions were produced, it had been quietly dropped from the record. Today, there is no visible trace of it at ground level whatsoever.

The 1838 Ordnance Survey six-inch series was one of the most thorough mapping exercises ever carried out in Ireland, completed by teams who walked the land and recorded what they found with considerable care. When they noted an embanked enclosure at Carrowcastle, they were almost certainly recording something real, even if modest in scale. Embanked enclosures of this rough size can represent a range of things, from early medieval ring-ditches to small stock enclosures, and without excavation it is impossible to say what this one was. What can be said is that something was there in 1838 and, for whatever reason, either fell apart or was levelled in the decades that followed. Fifteen metres to the south, a ruined vernacular farmstead still stands in a partial way, a reminder that this corner of Mayo was once more actively worked than it appears now.