Gun emplacements like these have been built up and down the coast, and around the shores of Sydney Harbour. The first emplacement, built in 1788, was designed as a signalling station to notify the arrival of a ship. Then in 1839, the undetected arrival of ships, from the fast developing USA, caused a great concern. This triggered the building of the well-known fortifications at Bradleys Head and Fort Denison, as well as these ones at South Head. Another enemy at the time, France, then joined a campaign against a newer enemy - the Russians - in 1853, which prompted the completion of these gun emplacements. Guns were installed in 1872. In WWII, it was a Japanese enemy who these guns were trying to keep out, then in 1944, when the threat of invasion was less of a concern, the emplacements where disarmed.