What makes it immediately unusual is its shape: it belongs to a family of early Irish ecclesiastical buildings known as boat-shaped oratories, so called because their slightly bowed walls and tapering plan echo the upturned hull of a currach. The form is rare enough to draw attention even in a county well supplied with early Christian remains.

The structure measures just 5.7 metres by 5.1 metres externally, with walls a metre thick and drystone construction throughout, meaning no mortar was used at any stage. Despite the loss of its corbelled roof, a technique in which courses of stone are progressively stepped inward until they meet at the crown, the walls at the western end still stand to an internal height of 2.55 metres, and the vault was probably closed at around 2.75 metres above the original floor level. The quality of the stonework is notable: the long corner quoins are neatly angled, the external faces worked smooth, and the internal walls dressed to a very flat finish, suggesting skilled and deliberate construction rather than rough field assembly. The eastern wall carries a tiny window, barely 44 centimetres high and 34 centimetres wide, fitted with slightly inclining jambs and a deeply stepped sill; two projecting slabs with pivot-holes almost certainly held a wooden shutter. The western doorway is lower still, only 65 centimetres above ground on the outside and inclining to a mere 45 centimetres beneath its lintel head, requiring anyone entering to crouch considerably. Two slabs above the lintel retain squared perforations that once secured the door frame itself. The oratory sits within an artificial rectangular terrace, roughly 35 metres north to south by 14 metres east to west, reveted in drystone at its south-eastern edge. As late as 1902, religious rounds were still being performed at the site, with participants walking the perimeter of this terrace as part of the devotional circuit.