The development will include 19 one-bedroom villas as well as a restaurant and areas to host weddings and funerals.

The state government is supporting the project with $1 million from its Nature-Based Tourism Co-Investment Fund.

The construction, design, and fit-out will use predominantly local South Australian products and suppliers, and provide for 65 jobs once open to guests in April 2023.

Environment Minister David Speirs said the project was part of the Parks 2025 strategy which was delivering record funding for the environment and helping businesses deliver sustainable, quality tourism experiences.

"This project is a perfect example of how nature-based tourism can exist without impacting the natural environment visitors seek to experience," he said.

"Adelaide has been recognised as the most liveable city in Australia and third-most in the world and projects such as this will only enhance this reputation."

As part of the funding agreement, the developers Mount Lofty Properties will also provide support for koala research through the not-for-profit organisation Koala Life, which is based at Cleland Wildlife Park, and a contribution to the park's volunteers program.

Owner David Horbelt said the creation of a boutique retreat would bring a new level of international and interstate interest and visitation to the region.

"The retreat will offer guests an unparalleled journey of discovery focused on the abundant nature in the region including the conservation efforts at Cleland to preserve the future of the koala," he said.

"The intimate experience will connect guests with some of Australia's most iconic and treasured wildlife, along with an opportunity to connect with the wildlife eco-system located in the state's most coveted nature park setting."

Australian Associated Press