Fort Nepean Fort Nepean is a former defensive facility occupying part of Point Nepean , Victoria , Australia . It was part of a network of fortifications , commanded from Fort Queenscliff , protecting the narrow entrance to Port Phillip . Background . Following the 1875 – 76 Royal Commission into the Volunteer Forces , the Victorian Government invited the Director of Works and Fortifications in London , Lieutenant General Sir William Jervois , to Victoria to further advise on Victoria ' s defences . He arrived in 1873 accompanied by the Colonel Scratchley . Their joint report recommended that the basic defences for the Colony should be concentrated on the Heads , and consist of fortifications at the entrance to the Bay and on the shoals between the main shipping channels . Fortifications and guns . Fortifications and barracks were built on Point Nepean from 1873 and gun batteries were installed in 1886 . By the 1890s Fort Nepean was known as " Victoria ' s Gibraltar " . The barracks housed a Company of the Royal Victoria Volunteer Artillery Regiment . 1878 – 1880 . The first coastal defence guns on the site were four 80 pounder Rifled Muzzle Loading guns in two temporary sandbagged batteries . These were moved into more substantial earth emplacements from 1880 . 1886 – 1890 . Ten gun emplacements were constructed between 1886 and 1890 but not all had guns installed . By 1890 there were four 6 inch breach loading ( BL ) disappearing gun s , two BL 9 . 2 inch ( 234 mm ) Mk VI breech - loading ' counter bombardment ' British Armstrong guns , a 4 . 7 inch quick firing ( QF ) gun and a QF 14 pounder . One of the former 80 pounder emplacements was used as an observation post and one new emplacement was used as an armourer ' s store . Two of the same type of BL 9 . 2 inch ( 234 mm ) Mk VI gun were installed at Fort Queenscliff . One each of the guns was installed at Ben Buckler Gun Battery , Signal Hill Battery , and Steel Point Battery in Sydney . The barrel of the Signal Hill gun is on display at the Royal Australian Artillery Museum at North Fort , North Head , in Sydney . The Ben Buckler gun has been recovered and is awaiting restoration . 1907 – 1915 . From 1911 the fort was manned by the newly renamed Royal Australian Garrison Artillery and the Royal Australian Engineers . With war in Europe looming , longer range 6 inch Mk VII guns replaced the 9 . 2 inch guns . One of the 6 inch BL guns was removed and the 14 pounder was moved to Fort Queenscliff . The 4 . 7 inch QF gun was removed and the emplacement fitted with a searchlight , along with an engine house to generate electricity . The remaining gun emplacements were renumbered – the Mk VII guns were numbered A1 and B1 , and the 6 inch BL guns numbered F1 and H1 . 1939 – 1942 . Light anti - aircraft guns were deployed at the fort in 1939 . The remaining 6 inch BL guns were removed in 1940 . The A1 and B1 emplacements were renumbered F1 and H1 respectively , and fitted with concrete hoods . World Wars . The first Australian shots ( many sources report the first Allied shots ) of both World War I and World War II were fired from Fort Nepean . On 5 August 1914 , the German ship SS " Pfalz " attempted to escape from Port Phillip . Within minutes of being notified that war had been declared , Lieutenant - Colonel Sandford at Fort Queenscliff gave an order to Lieutenant C Morris , the Fire Commander at Fort Nepean , to " stop her or sink her " . After the " Pfalz " ignored signals to halt , the B1 gun fired across her bow . The " Pfalz " then turned around and the crew was arrested at Portsea . At 1 . 30am on 4 September 1939 , within hours of war being declared , the A1 gun fired across the bow of a ship which failed to identify itself . The ship then identified as the Australian freighter SS " Woniora " . These were the only occasions any of the Port Phillip batteries fired in anger . After World War II . With the removal of coastal artillery after World War II , the guns were dismantled and sold for scrap . The barrels of the historic Mk VII guns which fired in anger were retrieved from the Port Wakefield artillery proving ground and a scrap yard at Brooklyn , Victoria in the 1960s and returned to the fort . National Park . The area was opened to the public in 1988 upon the formation of the Point Nepean National Park .