Stack Rock Fort

Stack Rock Fort stands on a small island in Milford Haven Waterway, Pembrokeshire. A three-gun tower was built between 1850 and 1852, then encased in a larger limestone battery from 1859 to 1871. The fort was designed to protect Pembroke Dockyard from sea attack after French threats grew under Napoleon III. Its walls were later strengthened with granite piers and iron gun shields. The fort’s top floor once housed quarters for officers and men, while three planned gun turrets were never fitted. During the First World War it monitored the harbour with searchlights and remote-controlled mines. The fort’s armament changed several times. It began with three 32-pounder guns and later carried sixteen 10-inch and seven 9-inch Rifled Muzzle Loaders. By 1902 these were replaced by four quick-firing 12-pounders. A small garrison of one officer and thirty men usually manned the fort in peacetime. The Royal Dockyard at Pembroke Dock never came under attack while the fort was active. After decommissioning in 1929, it served briefly as a RAF communications post during the Second World War. Visitors find a solid limestone structure rising from the tidal island. The original gun tower remains inside the encasing walls, its elliptical shape still visible. The fort’s roof shows the scars of uninstalled gun turrets and searchlight emplacements. The surrounding waterway offers wide views across Milford Haven to Pembroke Dock and the hills beyond. The fort’s isolated position makes it a striking landmark in the estuary landscape.