For those interested in a 3 hour walk a couple of hours from Melbourne, i could recommend the Canyon walk which i visited last week . It starts about 10 minutes from Lorne at The Sheoak Picnic Area. The three waterfalls were all flowing nicely and ideal for a dip on a warm day. Not to mention the Canyon and abundance of shade. Although its close proximity to Lorne, we didn't come across too many humans.
We camped at Lake Elizabeth which is just out of Forrest. The undulating grounds would have to be one of the most pretty i've come across. A 20 minute walk takes you to the hauntingly beautiful lake where you can do a 2 hour loop walk and if done at dawn or dusk, maybe spot an elusive platypus. I didn't as i was outvoted by the family... next time.