Most visitors who make it to this uninhabited island off Kilrush come for the early Christian round tower and monastic remains associated with St Senán, so the military structure at the far end of the island tends to receive rather less attention. That is something of an oversight, because the battery is a well-preserved example of the coastal defence works that once guarded one of Ireland's most strategically significant waterways.

The battery was one of several erected along the Shannon Estuary in the early nineteenth century to protect shipping moving through the channel. Its layout follows a standard pattern used across the estuary: a semicircular or D-shaped plan with six guns arranged around the perimeter, the whole enclosed by a dry moat. A rectangular blockhouse was constructed within the moat on the landward side to protect the battery's rear, the side most vulnerable to attack from the island itself. Two walls situated roughly twenty metres apart at the base of a slope to the north may have served as infantry defences, suggesting the garrison anticipated a threat from more than just seaborne enemies. A note recorded by military historian Paul Kerrigan indicates that in 1811 Scattery was documented as having eight guns, possibly mounted in a temporary battery that pre-dated the permanent structure seen today. The naturally defensive character of the southern promontory would have made it an obvious choice for such an installation from the outset.

Reaching the battery means first crossing to Scattery Island by boat from Kilrush, and then walking to the island's southern extremity. The site is a national monument in state care, and the structure is reported to be in good condition, so the essential features, the curved parapet, the dry moat, and the outline of the blockhouse, remain clearly legible on the ground.