Great landmarks to see when visiting Australia. The geotour starts at The Great Barrier Reef.  The Great Barrier Reef The Great Barrier Reef can be seen from space. It has nine hundred islands stretching over it and more than 2900 individual reefs. The Great Barrier Reef is the worldâ??s biggest structure made by living organisms. It also has been named one of the seven  Uluru Ayers Rock aka Uluru is the second biggest monolith [the largest monolith is Mt.Augustus] in the world. It is named after Sir Henry Ayers [the chief secretary of South Australia] later renamed Ayers rock. The sandstone formation stands at 1,142ft and meas  Sydney Harbour Bridge Sydney Harbour Bridge is a steel arch bridge that carries all sorts of vehicles. It is nicknamed the Coathanger because of its shape. It was opened in the 19 march 1932. Its total length is 3,770ft and crosses port Jackson. Until 1967 it was the cities la  Sydney Opera House Sydney Opera House is an art centre on Bennelong point in Sydney. It is one of the 20th centuryâ??s most characteristic building and one of the worlds most famous art performing centres. There are over 1,500 performances each year attended by 1.2million p  The Three Sisters The Three Sisters are a rock formation. They are located in the Blue Mountains of New South Wales, they are near to the town of Katoomba and are one of the mountains most famous sites. Their names are Meehni (922m), Wimlah (918m) and Gunnedoo (906m). The