LIONEL Buckett sails through life with his head in the clouds and his feet deeply planted in the ground.

His family have owned large swathes of land in the Blue Mountains since the 1950s, and he has now carved out a fantasy cave cabin looking out over some of Australia’s most magnificent bushland.

“I’ve got lots of connections with this beautiful place,” he says of his 600 acres of land verged by World Heritage listed rainforest.

Up on a natural rock platform, he has built a spectacular concrete and steel construction with a small, round wooden door and a sandstone kitchen.

The fairytale bathroom has a hand-carved stone basin, long-drop toilet and an outdoor shower so guests can feel as though they’re standing under a waterfall.

Double-glazed glass doors seal off the cave in bad weather, but Lionel prefers to keep them open. “You can see the clouds, hear the water,” he tells news.com.au. “I sit there and feel as though I’ve gone a million years back in time. It hasn’t changed in ten million, and it was an active volcano 20 million years ago.

“There’s been no human interference. It’s easy to be inspired when you look at that.”

Lionel, 55, has been dreaming up wild projects like this for years, honing his skills building eco-friendly holiday cabins and a remarkable treehouse with its own spa and kitchen.

He uses convict tools and energy-efficient design features, including solar power and a corkscrew copper pipe that captures waste heat.

Jamie Andrei, who has made a short film about Lionel’s extraordinary project for TedxSydney’s 2015 film program, describes the cave as “Grand Designs meets Gaudi”.

“Living in the city, I’ve got a lot of mates who say they’ll do this or that and never do,” he told news.com.au. “The cave feels rock-solid in its protected nook. It’s amazing to see. The sunsets are stunning, the birds fly past, you can unwind in the stillness. It’s a little sanctuary.”

Lionel’s company, Australian Hardwood Homes, was using sustainable building techniques decades ahead of others, and it’s left the Gerringong-born designer with a coterie of talented associates to help make his visions come to life.

“I have a stonemason friend who does fine carvings,” he says. “He carved a lobster, a platypus and a pheasant’s tail out ironstone and set it in the roof.”

The Aboriginal-style carvings are similar to ones seen in the rock nearby, and they tell a story.

Lieutenant Bowen, who used to chop down wood here in 1830, wrote in his diary that he didn’t like spending time with convicts, so he started socialising with an Aboriginal group. They had lunch together, they would borrow his shoes, and they brought him presents: the baby platypus that inspired the name of the creek; yabbies; and the lyre birds that today imitate the sounds of Lionel’s power tools.

“People are gobsmacked by the sheer beauty of the land,” he says. “It’s spectacularly beautiful.”

He’s almost ready to share his magical creation with the rest of the world, starting with guests he already knows. But the building remains movable.

“I might change it,” he adds airily. “Depending on my experiences, how the sun sets, how the winds change.”

Visit the TedxSydney website to find out more about 2015’s film program, which promises to engage and educate in unexpected ways.