Welcome to Heritage NSW. Explore the Aboriginal, environmental, built and archaeological heritage of NSW and learn how to protect, celebrate and conserve it. Our heritage includes the places, objects and stories that we have inherited from the past and want to protect for future generations. Identifying and listing items of heritage significance are the first steps in protecting and managing those places and objects that we as a community want to keep.

They were launched from a group of five larger submarines waiting off the Heads. All three midget submarines were lost, with two of them destroyed before they could fire their torpedoes. Reactions by Sydney residents varied; a few made plans to flee the city, but many came to watch the recovery of the submarines. A week after the midget submarine attack on Sydney Harbour, two of the larger submarines returned to bombard Sydney and Newcastle with their deck guns. One shelled Newcastle for twenty minutes until driven off by fire from coastal artillery defences. Another submarine fired ten rounds into eastern Sydney. Little damage was done and the attacks appear to have inspired more curiosity than panic.

On 29 May five large Japanese I Class submarines rendezvoused some 35 nautical miles northeast of the entrance to Sydney Harbour. Before daylight the next morning an E14Y Glen float plane launched from one of the submarines, I , and crewed by Warrant Flying officer Susumo Ito and Ordinary Seaman Iwasaki, flew a daring reconnaissance mission over the harbour, twice circling the cruiser USS Chicago before flying off to the east. The aerial intrusion was observed and reported but it did not initiate any special harbour defensive measures being implemented.

On the night of 31 May — 1 June, three Ko-hyoteki -class midget submarines , M, M and M each with a two-member crew, entered Sydney Harbour , avoided the partially constructed Sydney Harbour anti-submarine boom net , and attempted to sink Allied warships. Two of the midget submarines were detected and attacked before they could engage any Allied vessels. The crew of M scuttled their submarine, whilst M was successfully attacked and sunk. The crew of M killed themselves. These submarines were later recovered by the Allies.