Sydney Harbour defences

33°50′18″S 151°15′21″E / 33.838450°S 151.255930°E / -33.838450; 151.255930 Sydney Harbour was protected by coastal batteries and other fixed defences from the early 19th century until the 1960s. These defences were constructed to protect the Australian city of Sydney from attack by enemy warships and submarines.^[1]