From the WHC Inscription
Inaugurated in 1973, the Sydney Opera House is a great architectural work of the 20th century that brings together multiple strands of creativity and innovation in both architectural form and structural design. A great urban sculpture set in a remarkable waterscape, at the tip of a peninsula projecting into Sydney Harbour, the building has had an enduring influence on architecture. The Sydney Opera House comprises three groups of interlocking vaulted ‘shells’ which roof two main performance halls and a restaurant. These shell-structures are set upon a vast platform and are surrounded by terrace areas that function as pedestrian concourses. In 1957, when the project of the Sydney Opera House was awarded by an international jury to Danish architect Jørn Utzon, it marked a radically new approach to construction.
Read more: http://whc.unesco.org/en/list/166