The lime and basil ice cream at the Frosty Mango café made a big impression on Matilda, but it was nothing compared to the kicks she gave and got as she swam in the clear waters of Big Crystal Creek.

Tattooed youths from Townsville tombstoning off the rocks, her mother, Katy, swooshing her underwater, eucalyptus leaves swirling in the currents, cockatoos racketing overhead — it’s all just great when you live in tropical North Queensland and you’re only 11 months old. The last time Jane and I had seen our granddaughter she was a skinny newborn mite, so to see her revelling in the Australian dream of fresh air, sunshine and water was a delight.

It was hard to tear ourselves away from Big Crystal Creek, but the rainforest mountains of the Paluma Range were beckoning across the valley.

Back in Katy’s car we went spiralling up Mount Spec Road, built on the flanks of the mountains with great hardship and sweated effort by unemployed Queenslanders in the hungry 1930s.

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Paluma village, at over 2,000ft, was a scatter of houses and tea rooms. Beyond the tiny, tree-shaded settlement the road swapped tarmac for dirt, looping among cycads and ironbarks to arrive at last at our accommodation high in the rainforest.

Hidden Valley Cabins is Australia’s first carbon-neutral holiday resort; all its electricity is generated through solar power. If that smacks of a sandals-and-muesli regimen, the reality is quite different.

The ten wooden-walled accommodation lodges are set in well-kept gardens among the trees; there’s excellent cooking courtesy of hostess Bonnie McLennan, plenty of cold beer and wine, and excursions, mini-safaris and rainforest adventures led by Bonnie’s husband, Ian, their son, Ross and his partner, Chelsea. It’s a conscientious set-up, but not a sanctimonious one.

That first evening we ate steaks on the veranda, shot inexpert pool and chatted with Bonnie, hearing how she and Ian gave up the tough life of Outback tin-mining to take on the challenge of modernising Hidden Valley.

The next morning Jane and I went walking up a track behind the resort to a rocky outlook over many miles of mountain landscape. The afternoon was spent hiking up the local creek with Matilda in the backpack, then unleashing her into a swimming hole to let her chortle and beat the water with her chubby fists.

Ross took time out to guide us on a trek through ironbark woodland to the rim of the spectacular Running River Gorge. This is set among ancient hoop pines that were already many hundreds of years old when white settlers appropriated huge swaths of Aboriginal land here in the late 19th century.

Down by the river at dusk we sat spellbound by the sleek forms of duck-billed platypuses as they swam and dived through their own ripples. Most unforgettable of all, perhaps, was the night walk we took through the rainforest with Bonnie and Ian, our torches disclosing wallaroos and brush-tailed possums, bumpy rocket frogs, and rufous bettongs, like giant, bouncy rats.

Boobook owls softly called, orb-weaver spiders glowed brilliant gold in their intricate wheels of web, and greater gliders and their tiny, shy cousins, the feathertail gliders, cut dark shapes across the full moon above the eucalyptus tops. It was magical to be there in the living, breathing forest as it went about its nocturnal affairs, regardless of us wandering along its moonlit ways.

Valley’s green tally

0 overall carbon emissions from Hidden Valley

2 inches covering the toe-to-toe span of the garden orb-weaver spider

5 number of times the greater glider is longer than the feathertail glider, nose to tail (30in compared with 6in)

90 number of solar panels at Hidden Valley

100 percentage of the resort’s electricity that is solar powered 78 tonnes of CO2 emissions saved a year by solar power at Hidden Valley. 26,000 litres of diesel saved every year by using solar power

130-plus bird species listed in the resort

200,000 number of electrical sensors and touch-sensitive sensors in a platypus’s bill

200,000,000 number of years that the hoop pine tree has grown in Hidden Valley

Need to know

Getting there Qantas (08457 747767, www.qantas.com) has return flights to Cairns from £669, for travel between April 16 and June 20.

Staying Hidden Valley Cabins (00 61 7 4770 8088 or 1800 466 509, www.hiddenvalley cabins.com.au) are self or fully catered. Double en suites from £78.

Car hire: www.avis.co.uk

Further information www.australia.com

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