The world’s oldest rainforest (yes, older than the Amazon) offers hikes that range from easy to challenging, dense jungles, beautiful mountains, waterfalls, wildlife, and cliffs. Make sure you spend a few days hiking around and getting out of touristy Cairns. If you really want to get off the beaten path, head all the way up to Cape Tribulation, and enjoy some real peace and quiet (just watch out for jellyfish when you go swimming. There are few folks to help if something goes wrong). There a lot of tour companies in the area but I like Uncle Brian’s tours the best (though he goes more into Atherton Tablelands and not up super far north).