The ringfort at Chanonstown measures roughly 31 metres north to south and 38 metres east to west, its perimeter defined by an earthen bank that has survived in the landscape long after the agricultural activity around it transformed the terrain. What makes the site particularly interesting is what appears beyond that primary enclosure: to the south and east, traces of a possible outer enclosure are visible, forming what has been described as a bailey-type area, though whether this feature is man-made or simply a natural scarp in the topography has not been conclusively determined.

Ringforts are among the most common monuments in Ireland, typically dating from the early medieval period, roughly the fifth to the twelfth centuries, and serving as enclosed farmsteads for a single family or household. They are usually defined by a circular bank and ditch, with the bank constructed from the upcast of the ditch. The Chanonstown example sits on ground that has since been drained and put to grass, which means the visual relationship between the fort and its original landscape has shifted considerably. The suggestion of a bailey-type outer enclosure is worth noting: a bailey, in the context of Norman fortification, refers to a walled or banked courtyard attached to a main defended area. Whether the feature here represents a genuine secondary enclosure added to an earlier ringfort, or simply a coincidence of landform, remains an open question. A second ringfort is recorded approximately 40 metres to the north, which suggests this part of Chanonstown once supported a cluster of enclosed settlement activity rather than an isolated farmstead.