The National Maritime Museum sits at Darling Harbour with a working waterfront of historic vessels moored alongside. Inside, the galleries cover Australia's relationship with the sea from the First Nations' bark canoes to the America's Cup. The most unusual exhibit is HMAS Onslow, a decommissioned Royal Australian Navy submarine you can crawl through — a claustrophobic but fascinating experience.
The museum's outdoor displays include a replica of Captain Cook's Endeavour, a destroyer, a lighthouse tender and various smaller craft. Entry to some vessels is included in the general admission; others require separate tickets. The rooftop of the main building has views over Darling Harbour toward the city and is open during museum hours.