The Sydney Opera House officially opened

On October 20, 1973, Queen Elizabeth II officially opened the Sydney Opera House on Bennelong Point, capping one of the most fraught building projects of the century. A vast crowd gathered on the harbour foreshore for the ceremony, complete with fireworks and a performance of Beethoven’s Ninth.

The design had been chosen back in 1957, when the Danish architect Jorn Utzon won an international competition with his soaring shell-like “sails.” Realizing them proved far harder than anyone imagined. The project ran roughly a decade late and finished at about $102 million — many times its original estimate.

Utzon, who had resigned in 1966 amid bitter disputes, was not present to see it open.

The controversy faded; the building did not. Its interlocking white shells became an instant emblem of Sydney and of modern architecture itself. In 2007 UNESCO inscribed it on the World Heritage List, calling it a masterpiece — and the youngest cultural site so honored at the time.