Recently added to the World Heritage List as part of 11 convict sites, Cockatoo Island is Sydney's largest island, located by ferry from Circular Quay. Unique remnants of the island's history include solitary prison cells, hand carved silos, a guardhouse and convict workshops. The island was also an industrial school, a reformatory and one of Australia's biggest shipyards.

Cockatoo Island is open to the public daily, offering major events, exhibitions, venue hire, accommodation, tours, barbecues, picnic areas, a waterfront bar, licensed kiosk and business tenancy. It is managed by the Sydney Harbour Federation Trust, a self funding agency created by the Australian Government to improve access to former defence and Commonwealth sites.

Other sites include: Snapper Island in Sydney Harbour, Woolwich Dock, HMAS Platypus in Neutral Bay, Headland Park and Chowder Bay in Mosman, North Head Sanctuary in Manly, Marine Biological Station in Watsons Bay and Macquarie Lightstation in Vaucluse.