Luxury treehouse resort Secrets on the Lake in Montville, Sunshine Coast hinterland, up for sale

“The word ‘unique’ is very overdone,” said John Petralia, the Ray White Commercial Noosa & Sunshine Coast agent who’s selling the eco-resort.

“But you’ve honestly never seen anything like this. The quality of the buildings is incredible, and with such an eye for detail; even the windowsills are made of individual pieces of carved wood.

“It’s absolutely magnificent, and we’ve been getting interest from as far afield as the US, France and Asia, as well as Sydney, Melbourne, Brisbane and locally. It’s fired the imagination of everyone.”

Potential buyers are being invited to make offers for the property – Secrets on the Lake, near Montville, due east from Buddina on the coast – by July 27. 

As it was constructed by its current owners, it’s difficult to put a price on, but the replacement value would be more than $20 million.

Those owners, George and Aldy Johnston, are now planning to reluctantly tear themselves away from their magnum opus to take some retirement time out.

“It will be hard to part with, as it was always our dream to create something like this,” said George, 79. “But we’re not getting any younger, and maybe it’s now time for someone else to put their stamp on it. It’s time for us to move on.

“It’s been a lot of commitment and a lot of time, and we’d love someone else to enjoy it as much as we have. And it’s been quite gratifying hearing people who are coming over to look at it. Everyone says it’s so much more beautiful than even the photographs suggest.”

George, an electrician, house painter and fruit shop owner from Toowoomba, and his schoolteacher wife, Aldy, now also 79, first moved to the area to take up a farm in Baroon Pocket in 1984 where they grew watermelons, tomatoes, peas and kiwi fruit. 

They planned to build cabins along the nearby Obi Obi Creek for visitors. but the Queensland government had other ideas and announced plans to flood their valley to create Lake Baroon in a $40 million project to provide water to the Caloundra and Maroochy shires. 

Instead, the Johnstons bought up a neighbour’s land and then gradually built the haven they’d imagined, opening it up to visitors in 1997.

Today, it comprises those luxury treehouses with suspended fireplaces and fbespoke timber furniture, much of which was sculpted by one of the couple’s three children, Rob. 

Each of the cabins has its own theme, with stained-glass windows and sunken spas.

The heritage railway station offers more space and beds for larger groups, while there are also penthouse treehouses. Guests are served at the restaurant, Dining on the Deck, with wonderful views of the water, mountains and rainforest. 

There’s also an 18-seat private room, two caretakers’ apartments, the reception centre and an art gallery.

A colonial-style building on the foreshore, the Lake House, can be booked for conferences, weddings for up to 70 guests and special events. The property has solid bookings into 2024.

“We decided many years ago that we wanted to create something like this, grow all our own organic food and live somewhere beautiful,” said George, now also a grandfather to five. 

“My wife would like us to retire, so maybe I’ll build another house somewhere else.”

Petralia, who is marketing the property in partnership with Nathan Beasley from Remax, said Secrets on the Lake was internationally recognised and very well-known as a beautiful retreat where guests can be at one with nature.

“It could also be an excellent investment,” he said. “There’s huge growth potential and it even comes with development approval for more accommodation, so the number of rooms could be increased by 50 per cent.