The former HMAS Platypus is a waterfront industrial site nestled below the suburb of Neutral Bay on a quiet harbour inlet. It once supplied light to the streets and homes of North Sydney as the base for the North Shore Gas Company. Over the years the site has been transformed and its sandstone cliffs excavated: firstly for the gasworks, then a workshop for servicing torpedoes, and finally a base for Australia's submarines. The Harbour Trust took over management of the site in 2005. It is currently closed to the public.