A note from Samuel Lewis's 1837 gazetteer records its destruction almost in passing, comparable, he suggested, to a surviving tumulus at nearby Curraghbinny. The loss is a reminder that military engineers rarely had much patience for what lay beneath their chosen ground, and that this headland had been considered significant long before anyone thought to mount a cannon on it.

The site's military history is itself a palimpsest of successive urgencies. A map by Phillips in 1685 shows no fortification here at all, only a small blockhouse further south near Weaver's Point. By around 1690, however, a French cartographer named Goubet was recording what appear to be two lines of gun embrasures along the shoreline and a square bastioned fort further up the slope, almost certainly the 'James's Battery' thrown up by Jacobite forces and used against the Williamite navy that same year. Whether any of that structure survived into Camden Fort, built around 1798, is not known. By 1804 the fort held 26 pieces of ordnance; by 1837 its garrison had dwindled to a master-gunner and five men. Around 1870 the landward defences were substantially remodelled: a wide, irregular zig-zag ditch was cut, fitted with a caponier, a covered defensive passage built into the ditch to allow defenders to fire along it without exposure, and new shoreline works were added, including two piers and an emplacement for a Brennan torpedo, an early guided underwater weapon steered by wires from shore. The fort's underground infrastructure, passages, emplacements, and a large magazine, was extensive. It passed to the Irish government in 1938 and was renamed Dún Uí Mheachair, or Fort Meagher, sitting directly across the harbour entrance from Carlisle Fort on the opposite headland, the two positions together once forming a controlled chokepoint into one of Ireland's great natural anchorages.