Cloghane Signal Tower, Cloghane, Co. Cork

This was not an oversight but a design principle: a first-floor entrance meant that in the event of attack, the ladder could be drawn up and the tower sealed against anyone approaching from below. Two bays wide and rising through three stages, built of rubble stone with a pitched roof and traces of slate hanging still clinging to its walls, the structure now stands roofless and disused, one of a chain of such towers that once studded the coastline with a single shared purpose: watching the sea.

That purpose had a precise origin. In 1796 a French fleet attempted to land at Bantry Bay in support of Irish republican rebellion, and though storms and poor coordination scattered the ships before troops could disembark, the near miss left the British administration acutely aware of how exposed Ireland's coastline was. In response, a network of signal towers went up around the south, east and west coasts in the early nineteenth century, each built to a broadly similar square-plan design with that telltale first-floor entrance, intended to spot approaching ships and relay warnings rapidly along the coast, tower to tower, faster than any horseman could ride. Cloghane's tower, dated to 1805, belongs squarely to this generation of coastal defence architecture. A later single-storey extension was added to the north-east, with its own square-headed door and window openings finished in rendered concrete, and the whole site was enclosed within rubble stone boundary walls.

What makes the site more than a single-period ruin is the addition standing a short distance to the south: a small concrete look-out post built around 1940, flat-roofed with a canted front elevation and plain square-headed openings, put up during the Second World War as part of Ireland's coastal watch. It answers exactly the same brief as the Napoleonic-era tower beside it, watching for hostile ships and enabling rapid communication along the coast, but does so in an entirely different architectural language: poured concrete rather than rubble stone, low and flat-roofed rather than tall and gabled, built for twentieth-century warfare rather than the fear of a French landing. Seeing the two structures together, separated by well over a century yet serving the same watch over the same stretch of water, gives a compact lesson in how coastal defence changed, and how much it stayed the same.