Arnold, about an hour south of Cairns, Innisfail/Palmerston Misty Mountain tracks. Tropical Rainforest, old bullock routes connecting coastal farms to the Atherton Tablelands, elevation change is 3000ft or so, mixture of mountain bike and cut tracks up to grade 5 difficulty. Not sure how many good days walking is in there, but some of the trails are couple days worth...
https://www.npsr.qld.gov.au/parks/misty ... ing_aroundhttps://www.npsr.qld.gov.au/parks/misty ... al-map.pdfI don't know anything about the dedicated guided tour buses or connections, but an option to get onto the trail is
1.Regular greyhound buses from Cairns to Innisfail, about a 90min-2hr ride( or an hour by car)
2. A 35km taxi ride from Innisfail to the end of Mena Creek Road, the start of the Gorrel Trailhead.
Of course if you want real hard, visit any town on the coast there, pick a direction and just walk straight into the forest. 5 days crawling through that puts you in a select group of ability.
Just couple things I tell visitors which will sound like sucking eggs but anyway. Humidity saps water faster than dry air. Your body can't cool from evaporative cooling( sweat leaving the skin) because the air is too moisture laden. It loses more sweat to try and compensate. Also elevation will still get cool. People get caught out with minimal gear on the local mountain ranges ( 4000-5000ft) thinking the night temps will be the same as the coast.
Also probably worthwhile learning to identify the Stinging tree. Most the trails are cleared of it by national parks but if they have been slack it will appear near trails, creeks or any break in the canopy/sunlight. its probably most painful flora in the world, hairs inject a nerve toxin, harmless but the pain is 'very distracting'. You will be in the hurt locker for quite a few hours, residual effects up to 4 months( hurts whenever you touch it, get the sting area wet or cold). I don't go into trying to frighten Hikers with creepy crawly stories... after all we are all Australians and used to stuff like snakes etc. I just mention this in particular as National parks are getting really slack clearing it and brushing up against one will put a downer on a nice trip.