New conservation area created near Lithgow

After almost a century of advocacy, a "jewel in the crown" of Australia's natural beauty - home to rare plants and animals, stunning rock formations and lush forest - has been protected by the NSW government.

More than 30,000 hectares near Lithgow has been declared a nature reserve, with the state government on Saturday pledging $50 million to establish world-class ecotourism facilities in the area.

The Gardens of Stone Reserve was conceived in 1932 by Myles Dunphy, "the spiritual grandfather of the conservation movement in Australia".

Its declaration as a protected area nine decades later is the culmination of possibly the longest conservation campaign in the state's history, advocates say.

"It has been a long time coming but it was definitely worth the wait," Nature Conservation Council chief executive Chris Gambian said.

"This is a very significant addition to the state's conservation reserve system ... (and) one of the conservation movement's proudest days - it shows what people can achieve when they work together and stay focused and optimistic in the face of many setbacks."

The area is home to internationally significant rock formations and more than 80 threatened plant and animal species, including the giant dragonfly.

"It's got amazing mazes filled with turrets of sandstone that look like natural sculptures," former director of the Colong Foundation for Wilderness Keith Muir said.

"They're about castle size and you walk through them, and then you discover a field of wildflowers or you discover a trickling stream or a valley of amazing gnarled gum trees."

The protection announced on Saturday ends decades of heavy use of the area by the coal industry.

Some of the damage done to the wilderness can't be reversed, but the government's funding pledge will go a long way to make sure is accessible and in top shape for travellers to enjoy, Mr Muir said.

"There's nothing else like it in Australia."

"It is a jewel in the crown. It should have been protected long ago."

Premier Dominic Perrottet is also keen for the state's residents to enjoy the new park, promising upgraded lookouts, walking trails, a 4WD circuit and a mountain bike network on the cards.

"We're investing record amounts in our national parks to protect our natural gems while also generating new industries in our regions to support jobs and creating new iconic experiences so more people can enjoy our natural wonders," Mr Perrottet said.

However the "centrepiece of the investment" will be the Lost City Adventure Experience, which will include Australia's longest zipline, an elevated canyon walk, and a rock climbing course.

Mr Gambian says the new facilities will bolster the local economy and create jobs, but will also unlock a new ecotourism hub for the state.

"This part of the Blue Mountains has been largely unexplored by tourists - both those from Sydney and internationally - but the potential is enormous," he said.

"Many people have no idea there is scenery on the edge of Lithgow that rivals the best that Katoomba and Blackheath have to offer.

"Today's announcement will hopefully change that forever."