While I never believed the supernatural connotations of the Picnic at Hanging Rock story (the film of which quite scared me as a young boy), I had always assumed it was based on a true story. It turns out the entire thing was invented for the 1967 novel, and the story simply took on a life of its own:
http://skeptoid.com/episodes/4308
http://skeptoid.com/episodes/4308
Lindsay did her own part to start the rumors that the book was based on fact. In the book's introduction, she wrote the following:
Whether Picnic at Hanging Rock is fact or fiction, my readers must decide for themselves. As the fateful picnic took place in the year 1900, and all the characters who appear in this book are long since dead, it hardly seems important.Near the end of the book she also referenced a newspaper article from 1914 about the disappearances. Said article never existed outside of the author's imagination, but few people fact check something like that.