Completed in 1967, six years before Jørn Utzon’s Sydney Opera House, Australia Square was the first truly modern skyscraper on the continent and, arguably, the world’s tallest lightweight concrete building. The 50-story cylindrical tower once stood alone as the focal point of a full city-block development in Central Sydney and with a popular plaza that made the complex the first successful large-scale commercial project in Australia. Vienna-born emigré architect Harry Seidler (1923-2006) brought his Harvard GSD and Black Mountain College training and experience in the offices of Marcel Breuer and Oscar Niemeier to his adoptive Australia where he became the country’s leading postwar modernist from 1948 on. Australia Square also began Seidler’s creative collaboration with Italian structural engineer Pier Luigi Nervi, with whom he worked on a number of large projects.