The distinctive triangular shell shapes rising out to the sky evoke memories of a parade of sails that used to be a frequent sight at Sydney harbor. They make the Opera House, on par with the Statue of Liberty and the Eiffel Tower, an iconic shape, unmistakable for anything else, and as representative of its city as the other two monuments are of theirs. Like the other two, the Opera House was a hugely ambitious project: when Danish architect Jørn Utzon submitted his winning design, he did not yet have a practical method of building it and construction would take over a decade.

On this day, October 20, in 1973, in a gala opening ceremony led by Queen Elizabeth II and The Duke of Edinburgh, the Sydney Opera House opens.

Sergei Prokofiev’s War and Peace, produced by the Australian Opera, was the opening night performance two days later, at the 1,547-seat Opera Theatre. There are three more performance halls in the complex: the larger Concert Hall seats 2,679, and the small Drama Theatre and Music Room (now named the Playhouse) seat less than 500 each. Five restaurants round out the complex, along with six theatre bars and extensive foyers.