What makes the Kilcredaun battery quietly singular among the chain of coastal defences strung along the Shannon Estuary is not simply its position, commanding a stretch of water two miles wide, but the degree of thought given to what might happen if the threat came from the wrong direction entirely. It was built to be attacked from behind, and the architecture shows it.

Dated by a keystone above the guardhouse entrance to 1814, the battery was part of a wider programme of estuary defences constructed during the Napoleonic era, when the Shannon represented both a strategic vulnerability and a navigable route deep into Ireland. The main armament comprised six 24-pounder guns, each mounted on a traversing platform that pivoted on a front pin set behind the inner face of the parapet, giving a wide arc of fire over the channel below. The guardhouse, which survives in reasonable condition externally, is an unusually complex structure: its lower floor sits level with the base of the dry moat, fitted with musket-loops that allowed defenders to rake the ditch in the manner of a caponnière, a flanking gallery used to defend a moat from within. The upper floor, reached originally by a small drawbridge, has musket-loops covering the interior of the battery itself. So far, this is largely consistent with the other batteries along the estuary. What sets Kilcredaun apart is a further set of loops on the opposite wall of the upper floor, facing landward, covering the approach from the rear. This feature, according to military historian Paul Kerrigan, is found at no other battery in the group. On the roof, two additional guns on traversing platforms could sweep through roughly 270 degrees, covering both flanks and the ground behind. The battery was abandoned as a military post sometime in the middle or late nineteenth century, and since then much of the dressed stonework facing the dry moat has been stripped away, leaving the earthwork structure more exposed than it once was.