Next to the Ayers Rock, the Sydney Opera is the most identifiable and well-known Australian landmark, and probably the best-known opera house worldwide, at least in terms of its design. It is also a landmark in 20th century architecture, and of course, its location in exceedingly beautiful Sydney harbour is impossible to top. So any visit to Sydney would be incomplete without at least admiring the building from the outside, preferably from a ferry or a cruiseship. Having said that, I would say that this is also enough, and a visit of the interior of the building is not really necessary. It´s not particularly disappointing, there´s just not a whole lot to see. Still, when in Sydney, do as the Sydneysiders do and go to the opera!