If you hear the word, "Maralinga", you may well be confused. You may see Australians reacting with a mixture of embarassment, shame and regret. It is one of the darkest chapters in Australian history.

You may not know that Australia has some of the most radioactive and contaminated sites in the world. It was the result of extensive and destructive nuclear testing in the 1950s and early 190s. And "Maralinga" has become a catch-all term for this.

None of this was widely known until the Mclelland Royal Commission in 1984 attempted to get to the bottom of the issue.

Given it is the 40th anniversary of this Royal Commission, I decided to invite Professor Liz Tynan to the show. She is the leading historian on the subject and has written several books on the topic.

In the first part of this two part episode, we talk about the background of nuclear testing in Australia, and how Australia came to be in this awful position. We talk about the wider issues, the likely killing of indigenous Australians due to the tests, and general warnings to visitors to Australia.