The structure was never meant to last centuries; it was part of a coastal alarm network, a line of over eighty signal stations constructed by the British Board of Ordnance in the early nineteenth century to watch for a French invasion fleet. Spaced so that each station could relay visual signals to the next using naval signal posts, the chain ran clockwise from Dublin Bay all the way around the Irish coast to Malin Head in County Donegal. The nearest links in that chain to this site were at Black Ball Head, roughly ten and a half kilometres to the west-northwest, and at Sheep's Head, about the same distance to the south-southeast. When the threat of French invasion faded in the mid-1810s, the whole system was quietly wound down.

Construction here at Derrycreeveen was allocated £910 and ten shillings in 1804, and the tower was completed by 1805. It was originally a square-plan building, roughly 5.8 metres on each side, with walls nearly 80 centimetres thick, probably finished in weatherslating on the exterior as was common for Cork signal towers. The design included bartizans at the north corners, small corbelled turrets projecting from the wall face, and a machicolation above the first-floor entrance on the south elevation. A machicolation is an opening in a projecting parapet through which objects or materials could be dropped, here serving a defensive rather than decorative purpose. The tower survived largely intact for well over a century before lightning struck it in 1959; a storm in 1964 brought most of what remained crashing down. Today only low wall sections stand, the north elevation bulging slightly where the chimney flue once ran inside. About four metres to the north sits a small ancillary building in somewhat better condition, still standing to around two metres, with a fireplace and a square-headed doorway. Its walls carry inscribed initials reading R.E. for Royal Engineers, along with names and dates scratched in by soldiers over the nineteenth and early twentieth centuries. A sunken feature identified during a 2012 survey, set in the rounded part of the enclosure's south-west end, is understood to be the base of the signal mast itself. The tower sits within a wider militarised landscape on the island that includes Martello towers and early twentieth-century batteries, all layered across the same ground over successive generations of coastal anxiety.