Galah canyon is a great canyon in the lower reaches of Rocky Creek, Newnes Plateau. It has about 7 or so abseils up to 35m and a magnificent cathedral-like chamber at the end.
There is some wading involved so a wetsuit is optional, and there is a bit of a scramble at the exit (with a rope for assistance).
It is a longish day with about 12km walk. It may be lightly raining according to the current weather report.