Is located within Sunnyside Canyon. Peter Medbury first visited the canyon on 2 November 2008. Peter had contacted Dave Noble at the time and he told me (Peter) the canyon was named Sunnyside Canyon. It had been named Acoustic Canyon when first discovered (late 70s??) but it turned out the name had been used so it was renamed to Sunnyside Canyon. I’d have been surprised if the name hadn’t already been applied to that Chamber (but I could well be wrong). On a later bushwalk by the Bush Club Mike Keats track notes record, The famous hemispherical cave in the lower reaches was visited. Pacing it out, it has a diameter of about 24m, a height of about 15m including a domed ceiling. Droppings on the floor show evidence of an active roost for bats.