It is indeed based on a true story. The incident of the missing schoolgirls at Hanging Rock is real. This has led to a lot of speculation and theories. The story's adaptation into different forms of media has spread the mystery far and wide. Writers and filmmakers have tried to explore different aspects of what might have happened that day, but the true nature of the event remains somewhat of an enigma.
Yes, it is. The true events that inspired it have a certain eerie quality. It's about these schoolgirls who vanish while on a picnic at Hanging Rock. No one really knows exactly what happened to them in real life, and the fictional accounts have only deepened the mystery, with different interpretations over the years.