Middle Harbour in the context of "Sydney Harbour"

Port Jackson, commonly known as Sydney Harbour, is a natural harbour on the east coast of Australia, around which Sydney was built. 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 (part of the South Pacific Ocean). It is the location of significant landmarks such as the Sydney Opera House and Sydney Harbour Bridge. The location of the first European settlement and colony on the Australian mainland, Port Jackson has continued to play a key role in the history and development of Sydney.

Port Jackson, in the early days of the colony, was also used as a shorthand for Sydney and its environs. Thus, many botanists, see, e.g., Robert Brown's Prodromus Florae Novae Hollandiae et Insulae Van Diemen, described their specimens as having been collected at Port Jackson.