1. Cockatoo Island
Named for the noisy sulphur-crested parrots who squawk their ownership at high-decibels, this is the largest island in Sydney's harbour – 18 hectares in size and set at the intersection of the Parramatta and Lane Cove rivers – and was an Aboriginal fishing spot before it was turned into a prison to house convicts from Norfolk Island. Later incarnations as an industrial school for girls, a naval training ship for boys and a repair and building dock for the Royal Navy eventually gave way to it being opened to the public in 2007. Since then, it's earned a name hosting New Year's Eve celebrations and the Biennale of Sydney, as well as overnight camp-stays and guided historical walking tours.
Cockatoo Island ferries depart from Circular Quay, Mon-Fri 6.15am-11.45pm; Sat 6.45am-11.45pm; Sun 8.45am-8.45pm. Timetables and info: Transport for NSW. Adult $7.13