Sydney is a city in the country of Australia on Earth, and is the most populous city in Australia. Sydney is the state capital of New South Wales, and is the site of the first European colony in Australia, established in 1788 at Sydney Cove by Arthur Phillip, leader of the First Fleet from Britain.
Sydney is located on Australia's south-east coast. The city is built around Port Jackson, which includes Sydney Harbour, leading to the city's nickname, "the Harbour City". It is Australia's largest financial center and the economic capital.
Sydney is a major international tourist destination, often referred to as the international gateway of Australia, and is notable for its beaches and twin landmarks: the Sydney Opera House and the Harbour Bridge. The metropolitan area is surrounded by national parks, and contains many bays, rivers and inlets.
UNSC HIGHCOM
Sydney is host to a massive base, called HIGHCOM Facility Bravo-6, and the base three kilometers underneath it, "The Hive". It is where members of the UNSC Security Committee discuss matters concerning the safety of the UNSC, Earth, and its Colonies.
SSII
Sydney Synthetic Intellect Institute, or "Double S.I.", was a facility located in Sydney. SSII worked with the creation of AI constructs, theorizing new approaches and calculating the details necessary for the creation of the AI.