Sydney Harbour Bridge and opened in 1932. The bridge's design was influenced by the Hell Gate Bridge in New York City. It is the sixth longest spanning-arch bridge in the world and the tallest steel arch bridge, measuring from top to water level. It was also the world's widest long-span bridge, at wide, until construction of the new Port Mann Bridge in Vancouver was completed in 2012. The Sydney Harbour Bridge was added to the Australian National Heritage List on 19 March 2007 and to the New South Wales State Heritage Register on 25 June 1999. The southern end of the bridge is
Sydney Harbour anti-submarine boom net Sydney Harbour anti-submarine boom net The Sydney Harbour anti-submarine boom net was an anti-torpedo and submarine defence net that was in Sydney Harbour during World War II. It spanned the entire width of the harbour from Green Point, Watsons Bay to Georges Head, on the northern side of Sydney Harbour. The boom formed part of the Sydney Harbour defences which also included artillery batteries and patrol boats. Construction of the boom commenced in January 1942 and the boom and gates were fully operational by August 1942. For over three years, entry to Sydney Harbour was restricted by the boom net.