From reef to rainforest: uncover Cairns' hidden wonders beyond the blue

You expect the blue to hit you when you drop into Cairns in Far North Queensland, but it's the green that rushes the senses. The lush hills around the airport give way to tropical tranches of rampant growth before you've even fully reached the city itself.

Even there, the long thin ribbon of waterfront parkland is matched with pockets of garden and old growth that leave you in no doubt the equator is nearer than usual.

Once in the city, historic school buildings and former cloisters cluster together in the shadows of sleek, tall hotels. Backpacker hostels and standalone houses squeeze in, too. We're staying in the city centre area, at the Park Regis City Quays, which offers you entry into an area with a raft of options. There's the tiki-flavoured Coral Sea brewing, nestled unassumingly in Bank Lane. If you're after something a bit rowdier, the bars on Shield Street are close enough for both convenience and a hasty retreat.

The hotel, which overlooks the city's eastern end, is a short walk from the Cairns Aquarium, a perfect attraction after a late landing. The wander through golden sunset offers just enough time to soak up sights, such as the bustle of The Esplanade and the night markets, before the sun disappears.

It's that fading sunlight that offers the crux of tonight's attraction: the aquarium in its liminal phase, as day turns into night and the creatures respond accordingly. Our guide, ecologist Laura Lopresti, offers almost the only sound as we explore microcosms of ecosystems spanning Far North Queensland, from the freshwater rivers out to the reef and even deeper waters. The twilight setting captures the shift between diurnal and nocturnal species. While not everyone in the tanks wakes up immediately, it's just as engrossing to watch other species wind down for the evening. Napping eels yap their jaws as they lay otherwise still, with some fish taking their time to settle among the coral.

The calm of exploring with a small group captures the serenity of a scuba dive, especially when the darkened oceanarium near the end crescendoes into active cownose rays, reef sharks and more.

Dinner at the adjoining Dundee's seafood restaurant helps extend the experience. Fish in the showstopping whole-wall tank cluster while others drift into rest, and we tuck into the set menu - including chilli calamari and a prawn spaghetti.

The centrepiece of any trip to the tropics is the Great Barrier Reef. Heading out with Passions of Paradise on a scuba dive on Hastings Reef, we're trying our hands as marine biologists for a day. The citizen science program - also geared for snorkellers - combines all the joys of exploring the reef with insights on why, how, when and where the reef is changing.

As the bubbles clear out of your eyes and the scuba hiss kicks in, there's a moment to register everything is beautiful before you get to work rallying the wildlife around you. It quickly ramps up your appreciation for those who do it professionally. Is that scratch on the coral from a storm or a predator? Did you count that fish before, or is it another of the same species? Whoever complained about herding cats has never tried to keep track of wild fish.

The experience delivers a real sense of accomplishment despite, in my case, a woeful lack of natural aptitude. It's one thing to walk or wade through a beautiful garden, but it's another to see the signs indicating its health and challenges. Underwater, Drew silently points to creatures and then to his waterproof clipboard. Before you glance up from noting things down, the million-dollar scenery has rearranged. Despite the barriers to language, it's informative. Those scratches on coral, he explains via the clipboard, are signs of fish eating it. These empty shells are the snails devouring it. By the second pass, you have a better sense of what you're looking for. It's the kind of experience that you'll carry with you.

The Down Under full-day tour starts gently, a walk through the Cattana Wetlands on the outskirts of Cairns. Taking its name from a former owner and sugar cane farmer, Frank Cattana, the former sand mine site has regenerated into a stunningly secluded forest walk that makes you feel miles from anywhere despite the cars and houses just out of sight and earshot.

From there it's a twist up the Kuranda Range Road, where we receive a traditional welcome from representatives of the Djabugay people. Our guides, Errol and Georgina, welcome us in language and translate to English as they go. Then there's a calling to country ceremony, our group spread across a bridge and casting stones. It is a genuine highlight - a welcome in more than name.

There's a moment to soak in the raging beauty of the Barron Falls, or Din Din in the local language. The Kuranda train pulls away just as we arrive through the gentle mist to the lookout, leaving the landmark entirely ours for a few precious minutes. The tour meanders into the Tablelands, offering a tasting plate of local produce. It swings through papaya and coffee plantation Skybury, who hand-pick their fruit and turn some of it into alcohol. Then there's dessert at Emerald Creek Ice Creamery, where cinnamon takes pride of place beside dragonfruit and other less common flavours.

It ends on a high, back to Kuranda for a one-way, 7.5-kilometre trip on the Skyrail. The elevated cable car feels like a reprise of some of the highlights, carrying you over the World Heritage rainforest and Barron Falls, back down towards the city and that big blue yonder beyond. Even diving this deep into tropical North Queensland over a few days, it's hard not to feel like you've barely skimmed the surface of what's on offer.

The writer was a guest of Seibu Prince Hotels & Resorts