In 1975 Edith (Christine Schuler) rests on a log surrounded by boulders.
This location is closest to Hanging Rock point of interest number 8 “The Saddle” as marked on the Hanging Rock Information Brochure (available from the Hanging Rock Picnic Cafe).
Step into the picture with this Google Maps photo sphere:
To find Edith’s log go to the right of the “The Saddle” sign and then walk into the rocks behind.
Some 40 years after the scene was filmed, the remains of Edith’s log are still there.
To the left of the log is the gap Miranda entered the scene from and it’s also where Sgt. Bumpher stands while listening to Edith talk to Mam’selle:
Kinoimages has a great picture (below) taken at this spot during filming in 1975:
A publicity still with the girls together at the log was also taken here:
While not obvious at first sight, this is the same gap that Marion, Irma, and Miranda walk into when disappearing into “the Monolith”, but their disappearance is shot from the bottom of the gap. When you’re at Edith’s log, you’re standing at the top of the same gap and behind “the Monolith”.
“Michael” (Dominic Guard) tries to crawl up this gap when searching for the girls and it’s also the gap Albert climbed into to rescue Irma.