SYDNEY - Australians on Friday celebrate the 50th anniversary of the Sydney Opera House, lighting up the sails of a harbourside "masterpiece" that has become an international icon.
Fifty years to the day since Queen Elizabeth II opened the world's most recognised concert hall -- visited by about 11 million people a year -- the Opera House will draw crowds with a nighttime laser show.
Besides the party, the Opera House has been hosting events recalling its complex history.
The Opera House's Danish architect, Jorn Utzon, never set foot in the building that he designed after beating 232 others in a 1956 competition offering a prize of 5,000 Australian pounds -- a decade before dollars were introduced.
A few days before the 50th anniversary party, two of Utzon's children told an Opera House audience about the enduring impact the building has had on their family and the lives of others.
Construction of the innovative building took 14 years and the cost -- first estimated at Aus$7 million -- grew to Aus$102 million by completion, largely paid for by state lotteries.
The interlocking vaulted sails -- covered with more than one million Swedish-made tiles -- shelter two main performance halls and a restaurant, all resting on a vast concrete platform.
The result is a "great urban sculpture" UNESCO says, hailing it as a "daring and visionary experiment that has had an enduring influence on the emergent architecture of the late 20th century".
As well as serious architectural credentials, the Opera House has had its lighter moments, too.
In the 1980s a net was installed above the orchestra pit in the Joan Sutherland Theatre after a chicken featuring in an opera performance walked off the stage and landed on top of a cellist.