20 October 1973 October 19, 2012 Author: Staff The Sydney Opera House is opened. Famous Words of Inspiration..."Heed the still small voice that so seldom leads us wrong, and never into folly." Marquise du Deffand — Click here for more from Marquise du Deffand Related posts: 6 October 1973 8 March 1983 30 March 1981 11 August 1984 20 October 1967 Categories: History Tags: 1973, 20 October