The reason most people fly to Cairns: a full day on a fast catamaran to a pontoon or moored platform on the outer Great Barrier Reef, with snorkelling, certified or introductory diving, a semi-submersible and lunch on board. Choose a small-group operator for quieter reef and a bigger boat for comfort and facilities.
Full day, about 8 to 10 hours$$$Tickets on Tiqets → 
A true coral cay, a 45-minute cruise from Cairns, ringed by white sand and fringing reef and topped by a small rainforest. Snorkel straight off the beach, ride a glass-bottom boat, walk the boardwalks and be back in Cairns by late afternoon. The easiest way to meet the reef.
Full day, about 8 hours$$$Tickets on Tiqets → 
A rainforested continental island about 45 minutes from Cairns by fast ferry, with coral-rubble Nudey Beach, a summit walk to a lighthouse, kayaks and snorkelling on the fringing reef. More walking and a wilder feel than Green Island, and a good pick for active families.
Half or full day, about 5 to 8 hours$$Book on Viator → 
A heritage train that climbs from Cairns into the Barron Gorge rainforest, past waterfalls, tunnels and sweeping cuttings, to the village of Kuranda. One of Australia's most scenic rail journeys, best paired with Skyrail in the opposite direction for a loop.
About 3 to 4 hours return with time in Kuranda$$Tickets on Tiqets → 
A gondola glides just above the canopy of the Barron Gorge National Park from Smithfield to Kuranda, with boardwalk stops at two rainforest stations. A gentle, low-effort way to see the World Heritage rainforest from above and to ride a loop with the scenic railway.
About 90 minutes one way, half day with stops$$Tickets on Tiqets → 
The oldest tropical rainforest on Earth, a World Heritage forest of ferns, giant trees and cassowaries north of Port Douglas. Cross the Daintree River by cable ferry, take a guided walk or river cruise, and see why this is the wildest day trip from Cairns.
Full day, about 10 to 11 hours$$$Tickets on Tiqets → 
Where the rainforest meets the reef: a remote stretch of the Daintree coast with Myall and Cow Bay beaches, mangrove and rainforest boardwalks and wild coastline. Reach it on a full-day tour or an overnight stay, but never swim in the sea.
Full day, about 11 hours, or overnight$$$Tickets on Tiqets → A clear rainforest river tumbling over granite boulders at the southern edge of the Daintree, run by the Kuku Yalanji people. Start at the Mossman Gorge Centre, ride the shuttle in and take the Ngadiku Dreamtime Walk for an Indigenous guide's view of the forest.
About 1.5 hours for the guided walk$$Official site →
FreeA relaxed resort town about an hour north of Cairns, with Four Mile Beach, the Flagstaff Hill lookout, Macrossan Street cafes and markets, and the quickest access to the Low Isles, Agincourt Reef and the Daintree. A pleasant base or a day trip.
Half day to a few nightsDetails →
FreeCairns' free seafront: a 4,800-square-metre saltwater lagoon with lifeguards, shady lawns, free electric barbecues, playgrounds and a boardwalk along the mudflats. Stinger-free swimming all year, and the best place to wind down between reef days.