A new rock pool and aerial walkway will be centrepieces of a $3-million upgrade to the children's Naturescape playground in Kings Park, designed to get kids off their screens and into the bush.

The park was funded by Rio Tinto and opened in 2011. Environment Minister Albert Jacob said it was a world-leading initiative.

Mr Jacob said Rio had contributed $9 million in its partnership with Kings Park over the past eight years, and the expansion of the Naturescape would significantly enhance the natural play experience of children visiting the area.

"Over the next 12 months this Naturescape will be developed further again, providing a greater experience for kids and for families to get out and experience the natural bush," he said.

Rio Tinto's Zara Fisher said the purpose of the Naturescape was to help children connect with nature.

"The natural bush setting allows children the freedom to explore and discover, empowering them to become more informed, caring and effective environmental custodians for tomorrow," Ms Fisher said.

Mr Jacob said the Barnett Government had worked to open up natural areas and make them accessible to the public, particularly families and children.

He believed it was important children had the chance to experience the physical environment, even if it carried the risk of bumps and scratches.

"The kids who are growing up in an increasingly urbanised environment in WA have an opportunity to get out, to experience nature, to develop an appreciation for our Nature in WA," he said.

He said the park had already proven a model, inspiring similar nature play developments.