Galah Canyon is an excellent canyon in the lower reaches of Rocky Creek. It features a number of interesting abseils and a magnificent cathedral-like chamber at the end. It was discovered by Ted Daniels and Chris Cosgrove on a joint NPA-SUBW trip in 1977 and named due to its proximity to Galah Mountain.
See Newnes Plateau & South Wolgan Fire Trails for information on how to drive to the starting point. From the locked gate at the end of the Rocky Creek exit track at MGA467143 (AMG466141, Rock Hill), head N along the old fire trail, now really just a foot track. This contours around the north side of Galah Mountain, before heading down the ridge to the north. Stay on same track when the Rocky Creek exit track turns off to the right at MGA473148 (AMG472146). The old fire trail ends at a clearing at MGA477169 (AMG476167). Head NE along the ridge for 500m and then E and then SE to the bend in the creek at MGA482172 (AMG481170), avoiding cliffs. There is a short section of attractive canyon with a couple of deep wades in the top of the creek, including a short drop that you could leave a handline on to get back up on your way out, if you exit that way. A relatively easy creek walk follows before the main canyon starts at MGA491177 (AMG490175).
There are a couple of options for the first drop. Safest is probably to abseil 28m from the obvious gum tree just left of the creek. Alternatively abseil, scramble down the small gully on the left and abseil about 20m from a tree at the bottom. Be careful of loose rocks.
Then there is an awkward overhanging 5m abseil, followed by a slide or abseil down a log. A slightly dodgy slide into knee deep water follows, though there may be a log for a short abseil instead. Then there is a 7m abseil over a chockstone, followed by a drop of about 3m that can be abseiled or possibly scrambled. The final abseil is about 5m, just beyond a deep pool. However, the anchor is some way back (10m), and the waterfall is very slippery. Following this there is a bit more canyon, and a possible wade or short swim before it opens out near Rocky Creek.
Once the canyon opens out, traverse around to the right under the main cliff for about 200m until you are well above Rocky Creek. Just past a short exposed section across a slab, look up to the right for (hopefully) a rope hanging down from a tree. This climb of about 6m leads to a steep ramp and gully that takes you up through the cliff line. Continue around to the point and then head up to the top line of cliffs, and follow them along until you rejoin the creek. Continue up the creek and exit where you dropped in at the start. Alternatively you can exit at an amphitheatre on the right about 50m before the abseil in the upper section.
There are also other exits further upstream on Rocky Creek itself.