Port Jackson, commonly known as Sydney Harbour, is a natural harbour on the east coast of Australia, around which the city of Sydney is situated. It consists of the waters of Sydney Harbour, Middle Harbour, North Harbour, and the Lane Cove and Parramatta rivers. The harbour is an inlet of the Tasman Sea, which in turn is part of the South Pacific Ocean. It is the location of significant landmarks such as the Sydney Opera House and Sydney Harbour Bridge. As the location of the first permanent European settlement on the Australian mainland, Port Jackson has played a key role in the history of Sydney, as well as its social and economic development.