That detail alone says something about how the people stationed here understood their situation: perched some 253 metres above sea level on a small flat plateau edged by near-vertical cliffs to the north and west, keeping watch for a French invasion fleet that never came. The rubble-stone walls are largely fallen now, two sides gone almost entirely, but the northwest wall still stands to first-floor height and the fireplaces and flanking alcoves on its inner face remain legible. A machicolation once protected the doorway above; bartizans once guarded the north and east corners. Neither has survived. What we know of the full original form comes substantially from a sketch made in 1856 by the artist and geologist George Victor Du Noyer, who recorded details that had already begun to disappear by his time.

The tower was completed by 1805, part of a network of over eighty signal stations built by the British Board of Ordnance along the Irish coastline in direct response to the threat of Napoleonic invasion. Each station communicated with its neighbours using a naval signal post, and together they formed a continuous coastal chain running clockwise from Dublin Bay all the way to Malin Head in County Donegal. Ballydavid's nearest neighbours in the chain were the tower at Sybil Head, roughly 8.85 kilometres to the southwest, and Kerry Head some 37 kilometres to the northeast, though the Kerry Head tower has since been demolished. Intermediate barracks sites at Brandon Head and Rough Point at Kilshannig served the long stretch between; the Brandon Head structure has collapsed and the Kilshannig one is gone entirely. The whole network was quietly wound down by the mid-1810s once the invasion threat had faded. By the time of the first Ordnance Survey in 1841 and 1842, the site was already being mapped as ruins.

A rectangular enclosure wall, roughly 42 metres by 19 metres, surrounds the tower and two further buildings on the same plateau. The enclosure is slightly misaligned with the buildings it contains, which suggests it was added after the tower itself was laid out. The larger of the two ancillary buildings, positioned immediately to the northeast of the tower, seems to have been constructed sometime in the mid-to-late 1840s; it does not appear on the 1841 survey but is shown roofless in Du Noyer's 1856 sketch. A sunken pathway still leads from the entrance in the northeast wall of the enclosure down towards the buildings, and the entrance itself remains faintly visible on the ground.