Cockatoo Island is the largest island in Sydney Harbour in Sydney, New South Wales, Australia. Located at the junction of the Parramatta and Lane Cove rivers, Cockatoo Island is a former imperial prison, industrial school, reformatory and gaol. It was also the site of one of Australia's biggest shipyards during the twentieth century. The first of its two dry docks was built by convicts and was completed in 1857. The island's maritime industrial activity ceased in 1992. Cockatoo Island was inscribed on the World Heritage List in July 2010.
The island is managed by the Sydney Harbour Federation Trust which is also responsible for seven other lands around Sydney Harbour. The Harbour Trust is revitalising the island as a landmark harbour attraction with cultural events and heritage interpretation. Today Cockatoo Island retains many remnants of its past. Its prison buildings have been World Heritage listed, part of a serial listing of 11 Australian Convict Sites. Large workshops, slipways, wharves, residences and other buildings retain the texture of the island's industrial past.