Green Island
"An island that grew itself out of coral, then grew a forest on top out of spite."
A genuine coral cay wrapped in rainforest, close enough to Cairns for a day trip and strange enough to feel like a different planet.
The ferry out of Cairns takes forty-five minutes and somewhere around the halfway mark the water changes colour so abruptly that people on deck actually stop talking. Green Island is a true coral cay — not a continental island with a rocky spine, but a low sand deposit built up over thousands of years on top of a reef platform, then colonised by rainforest that somehow took root in the coral rubble and never left. You can walk the entire perimeter in under an hour. I did it barefoot at low tide, which I do not recommend, because the exposed reef flat is sharp in places most guidebooks gloss over.
What surprised me was how good the snorkelling is directly off the main beach, no boat required. I waded in past the roped swimming area and within five minutes was floating over parrotfish, a resting green turtle the size of a car tyre, and a giant clam wedged into a coral head with lips the colour of a bruise. The island sees a lot of day-trippers from Cairns, and by midday the water off the jetty gets crowded with glass-bottom boats and semi-submersibles, so I got there on the first ferry and had the best hour almost to myself.
The interior forest is small but genuinely dense — strangler figs, basket ferns, a boardwalk that loops through shade so complete it feels ten degrees cooler than the beach. There used to be a resort here that operated for decades before the island reverted to national park status for its non-day-visitor areas, and walking the boardwalk now, past old foundations reclaimed by roots, gives the whole place a slightly haunted, slowly-being-returned-to-nature feeling that I found more moving than I expected.
When to go: Visit June through October for the calmest seas and best underwater visibility, and take the earliest ferry you can — before ten in the morning the water off the main beach is still clear and mostly empty of the day-boat crowds that arrive by midday.