By that point, a two-storey signal tower, a probable barracks block, and at least two smaller outbuildings had all been constructed, occupied, and abandoned within living memory. The first edition six-inch map, surveyed in 1841 to 1842, shows a rectangular enclosure with a rounded northwestern end, the square tower at its centre, and several associated structures clustered within. The map labels the whole complex simply as 'Barrack and Signal Tower (in Ruins)'. By the time the second edition was surveyed in the 1890s, almost everything had gone, replaced by a single thin rectangular building overlying the tower's former footprint. That too has since disappeared, leaving only enclosed pasture to the east and rough ground falling away to the west.

The tower at Kerry Head was completed around 1804 to 1805, as part of a network of more than eighty signal stations constructed by the British Board of Ordnance along the Irish coastline. The purpose was straightforward and urgent: to provide early warning of a French invasion fleet. Each station used a naval signal post to communicate with its neighbours, passing messages along a continuous chain that ran clockwise from Dublin Bay all the way around the coast to Malin Head in County Donegal. Kerry Head sat within a particularly exposed stretch of that chain. The adjacent station to the north, at Loop Head in County Clare roughly 16.6 kilometres away, has also been demolished. To the southwest, the station at Ballydavid Head, about 37 kilometres distant, survives in ruinous form, and intermediate barracks sites at Rough Point, Kilshannig and at Brandon Head have likewise collapsed or been demolished. When the threat of French invasion receded in the mid-1810s, the whole system was abandoned, and the structures were left to decay or find secondary uses. The Kerry Head tower, which measured roughly 5.85 metres square, was already a ruin before the Ordnance Survey reached it. The surrounding landscape holds other traces of earlier occupation: the remains of St. Dahalin's Church lie about 4 kilometres to the east, and the coastal promontory fort at Cahercarbery Beg, a roughly circular enclosure of the kind defined by a wall or bank cutting across a headland, sits about 2 kilometres to the southwest.