Cairns is a base rather than a sight: what is worth doing is the reef, the rainforest behind town and the free saltwater lagoon on the Esplanade, and nearly all of it needs booking a day or more ahead.
Cairns Esplanade Lagoon
Free saltwater swimming lagoon on the Esplanade, with beach volleyball courts, fitness stations, three free playgrounds, showers, lockers and barbecue areas open 6am–9pm. It exists because the mudflats in front of the city are not swimmable. Dogs are allowed on the Esplanade but not in the lagoon or the parkland around it.
Kuranda Scenic Railway and Skyrail
The standard day trip: 37km of 1890s railway climbing 327m over 55 bridges and through 15 tunnels from Cairns to Kuranda, with the Skyrail cableway back down over the rainforest. Combined tickets are $145.50 adult and $79.50 child; morning trains leave Cairns Central at 8.30am and 9.30am and return from Kuranda at 2pm and 3.30pm.
Moore Reef pontoon
Full-day outer-reef trip with Sunlover from the Reef Fleet Terminal at 1 Spence Street, leaving 10.15am and back by 5.30pm with about four hours on the pontoon. $317 adult, $177 child, $816 for a family of four, including snorkel gear and stinger suit, glass-bottom boat, semi-submersible, underwater observatory, buffet lunch and a 30m waterslide.
Fitzroy Island
Continental island 45 minutes out on the Fitzroy Flyer from Berth 20 at Marlin Marina, with rainforest walking tracks and snorkelling straight off the beach. Ferries at 8am, 11am and 1.30pm; return day-trip fares from $99 adult and $55 child, and you must be at the wharf 30 minutes before departure.
Cairns Botanic Gardens
Free 44-hectare gardens with a visitor information centre, a library and self-guided walking tracks marked by coloured arrows, plus accessible route maps for wheelchair users. TANK sixty four cafe next to the visitor centre runs 7am–3pm daily. No pets except registered assistance animals, and no feeding the birds.