This one at Killiney sits roughly a quarter of a mile inland and some 250 feet above sea level, which gives it an odd quality among its kind. It is classified as Tower and Battery No. 7 in a numbered sequence running south of Dublin, part of a system that was not quite as uniform as that numbering implies: out of sixteen designated positions, only fourteen actually had towers, two locations having batteries alone, while several towers sat close to adjacent batteries rather than being directly paired with them.

Construction of the Dublin-area towers and their associated batteries began in 1804, overseen by Colonel Benjamin Fisher of the Royal Engineers, and the work moved quickly enough that by December 1805 all towers in the network were armed and complete. Martello towers, for those unfamiliar with the type, are squat, thick-walled cylindrical fortifications, originally developed in response to the threat of Napoleonic invasion. The battery at Tower No. 7 held three guns, specifically 24-pounders, and was linked to the tower on its south-east side. A single-storey structure was built against the tower at the rear of the battery, covered until relatively recently by a lean-to slate roof. Access between this ancillary building and the first floor of the tower was provided not by a conventional door or stair but by a vertical recess cut within the thickness of the tower wall itself, an arrangement that says something about how closely the garrison would have lived and worked within these confined structures.

The tower is located east of Killiney Hill Road, the R119, and sits within what is now an ordinary suburban housing area, which makes the first sight of it somewhat unexpected. Taylor's map of the environs of Dublin, surveyed in 1816 at a scale of two inches to one mile, already records the tower and battery at this location, giving some sense of how quickly the structure became a fixed landmark in the landscape. The tower and battery both survive, and the site repays a careful look for the relationship between the various elements, particularly the south-east connection between battery and tower, and whatever remains of the ancillary building at the rear.