The city is dominated by the harbor,which people have described as one of the most spectacular in the world.there are three things that you must not-and indeed cannot miss.first,there is Sydney harbor bridge,one of the largest single arch bridges in the world. Second,the Sydney Opera House is a famous landmark that most visitors greatly anticipate seeing. Finally don't miss Fort Denison,where prisoners were kept in solitary confinement for days on a diet of bread and water. The beat way to get around is by boat or hydrofoil,both of which have regular services leaving from Circular Quay. If you prefer to do things at your own pace,why not hire one of the many boats available for this purpose?