7. Prime Minister Harold Holt

One day, the Prime Minister went for a swim and never returned. A tale of highs, lows, politics and conspiracies. Follow us on INSTAGRAM & TWITTER @australianarama SOURCES: National Archives of Australia, ABC, Australian Prime Minister Centre, National Film and Sound Archive of Australia, Museum of Australian Democracy, Sydney Morning Herald, The New Daily. Learn more about your ad choices. Visit megaphone.fm/adchoices