It measures only about eighteen metres east to west and seventeen metres north to south, yet what it lacks in size it compensates for in deliberate construction. The entire perimeter is defined by a wide stone platform, revetted with an outer stone facing that remains best preserved along the eastern and western sides. The interior is composed of earth that rises slightly towards the centre, suggesting a raised living surface kept dry above the waterline.

The site is classified as a cashel, a term for a stone-built ringfort, a type of enclosed farmstead or defended residence common throughout early medieval Ireland, broadly from the fifth to the twelfth centuries. What makes this example particularly interesting is its relationship with the water around it. A stone causeway runs south-south-east from the island, presumably connecting it to the lake shore, and traces of what may have been landing places survive at both the north and south-south-west sides. This combination of a causeway and possible landing points suggests the island was intentionally designed for controlled access, with water acting as a natural defensive barrier in place of the earthen banks or ditches that characterise inland ringforts. The site shares qualities with crannogs, which are artificial lake islands more commonly associated with timber construction and waterlogged preservation, though this structure appears to rely on stone as its primary building material.