ONE Darling Harbour is about to become Sydney's latest landmark residential apartment building. Overlooking Sydney Harbour, each apartment will have spectacular views which will never be built out. It is conveniently located near all amenities including shopping centres, food halls, exhibition centres, museums and the new Sydney Casino which will be just five minutes walk away. It is also conveniently near transport facilities with the monorail station almost immediately outside which provides a direct connection with Chinatown. One Darling Harbour residential tower is being developed by Citistate Corporation and built by one of Australia's most prominent builders - Multiplex Constructions. The footings and foundations are already in place and construction of the main structure is due to begin soon with completion slated for March 1995. One Darling Harbour will comprise 215 luxury two-and three-bedroom apartments. Each apartment will be finished to a very high standard with an extensive use of granite and marble. ''The price for this luxury ranges from A$300,000 (about HK$1.6 million) to A$1.9 million and already the development has generated off the plan sales and a great deal of interest in Australia and Hongkong,'' said Jan McNally, residential manager of international property consultants Richard Ellis.