You're talking about the chossy moss filled thing up Mt Bishop (well that's what we used to call it when we lived there)? I think it's a pretty scary aid route with some low level free climbing isn't it? There's also some more climbing on some huge chossy cliffs up north a bit towards Daintree. I took my bouldering gear into the Gorge once and couldn't find anything. I know there's a significant waterfall about a 1/2 hour walk upstream but I couldn't be arsed walking up there. Have a look at the seaside areas between Pt Douglas and Cairns, there's some nice looking cliff lines there. Jullatten(sp?) also has quite a bit of rock around.