 The site was designated a National Historic Site of Canada in 1923.The Naval Yard was initially defended by its own large blockhouse, three redoubts and a fortified stone wall.These defences were enhanced and later replaced by the large network of army fortifications whose main purposes was to safeguard the Naval Dockyard including nearby Fort Needham, Fort George, the Halifax Citadel; York Redoubt; Fort Charlotte on Georges Island, Fort Clarence in Dartmouth; five forts on McNabs Island and extensive batteries at Point Pleasant.