What was recorded on the third edition of the Ordnance Survey six-inch map in 1934 as a clearly defined circular feature, roughly forty metres in diameter, is now so densely overgrown that only a partial arc of its earth and stone bank remains legible, running from the north around through the east to the south.

Enclosures of this type are among the most common archaeological features in the Irish countryside. They range in date from the Bronze Age through to the early medieval period, and were used variously as farmsteads, places of ritual, or enclosed settlement sites. Without excavation it is rarely possible to say which function any individual example served. What the surviving bank at Knockdoebeg does confirm is that someone, at some point, went to considerable effort to define and enclose this particular patch of ground, choosing a slight elevation above the surrounding grassland in the manner typical of such sites across Connacht.