The centrepiece of the investment will be the Lost City Adventure Experience, an iconic project, that will include Australia's longest zipline and a spectacular elevated canyon walk.

It will also feature NSW's first Via Ferrata rock-climbing opportunity, a protected climbing route employing steel cables, rungs or ladders, fixed to the rock that climbers can safely attach to.

Premier Dominic Perrottet said the NSW Government was investing $50 million to transform the area, which will be added to the national parks estate, into an eco-tourism and eco-adventure destination generating jobs and economic growth for the entire region.

"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.

"This new set of reserves will improve access to this spectacular region attracting domestic and international tourists with upgraded lookouts, walking trails, a 4WD circuit and a world class 35km mountain bike network."

Deputy Premier Paul Toole said this will be a massive boost for Lithgow's local economy, drawing an estimated 200,000-plus extra visitors to the region every year.

"This investment will deliver an iconic tourism and adventuring experience right on Sydney's doorstep and represents one of the State's largest ever investments in a regional ecotourism project," Mr Toole said.

"We expect this new set of reserves to create at least another 190 jobs for the Lithgow region, not to mention the millions of tourism dollars that will flow into the local economy."

READ MORE: Leo continues to raise money for the Gardens of Stone Alliance

Treasurer and Environment Minister Matt Kean said the new reserve will also feature one of the world's great long-distance walks extending from the Wollemi to the Gardens of Stone.

"This new set of reserves will rival the Three Sisters in Katoomba as the destination for visitors and tourists to the mountains west of Sydney," Mr Kean said.

"It will also provide a much-needed lasting legacy for the environment, protecting and providing habitat for numerous threatened and endangered species for future generations."

Centennial welcomed the announcement by the NSW Government to extend the Gardens of Stone National Park.

"Our current and future mining operations will continue to co-exist with this new State Conservation Area, which will deliver further economic diversity for our local Lithgow community and create a new accessible tourist destination for the general public to visit and enjoy," Executive General Manager External Relations Katie Brassil said.

The declaration of the Gardens of Stone State Conservation Area today is the culmination of potentially the longest conservation campaign in the state's history.

"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 the state's conservation reserve system - more than 30,000 hectares of stunning landscapes and wildlife habitat that the conservation movement has campaigned almost a century to protect.

"The Gardens of Stone reserve was conceived by Myles Dunphy, the spiritual grandfather of the conservation moment in Australia, as part of his broader vision for a Greater Blue Mountains National Park.

READ MORE: Tourist operators hear Destination Pagoda plan for Gardens of Stone region

"His vision has now been realised after one of the longest conservation campaigns in the state's history."

Mr Gambian said many people and organisations had contributed to the campaign to protect the Gardens of Stone, especially Keith Muir and the Colong Foundation for Wilderness, the Blue Mountains Conservation Society, the Lithgow Environment Group, Bushwalking NSW, the Colo Committee, National Parks Association of NSW, and the National Trust.

"This is one of the conservation movement's proudest days - it shows what people can achieve when they work together and stay focused and optimistic in face of many setbacks," Mr Gambian said.

"It is also a testament to what can be achieved when people of good will from all sides of politics - Liberals, Nationals, Labor, Greens and independents - focus on the common good and providing a legacy for future generations. They all deserve credit for what has been achieved today.

"I pay special tribute to Premier Dominic Perrottet, Deputy Premier and Bathurst MP Paul Toole, and Blue Mountains MP Trish Doyle."

Mr Gambian said the commitment of $50 million for tourist infrastructure and roads would grow Lithgow's ecotourism industry, bolster the local economy and create many jobs.

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

The Gardens of Stone Alliance (GOS Alliance) welcomes the NSW Government's announcement of the gazettal of the Gardens of Stone State Conservation Area.

READ MORE: Jack Mundey, CFMEU and conservationists discuss Gardens of Stone plan

Convenor of the GOS Alliance Wilson Harris said the GOS Alliance is absolutely thrilled that the NSW Government has announced the reservation of the Gardens of Stone State Conservation Area.

"We can't wait for it to be showcased and appropriately developed into a world-class destination," he said.

"This area has amazing values that are deserving of protection. The landscape is dotted with thousands of pagodas, with gorges, canyons and waterways weaving between them. There are valleys with lush rainforest, high-country woodlands and critically endangered wetlands that provide crucial habitat for countless threatened species."

Madi Maclean, Senior Vice President of the Blue Mountains Conservation Society said the Society is overjoyed that the spectacular Gardens of Stone area, north-west of the well known Blue Mountains, is at last protected as a State Conservation Area.

"This wonderful landscape of pagoda rock formations, cliffs and gorges, flowering swamps, rare plants and animals, waterfalls and stunning vistas will make Gardens of Stone a unique new reserve," she said.

"With ongoing management it will become a popular destination and an exceptional natural asset for the Lithgow area."

Keith Muir, former Director at the Colong Foundation for Wilderness, said that with professional management and effective protection, this reserve will become a must-see destination.

"Its pagodas are unique in the world, and this reserve will put Lithgow on the tourist map. Once basic visitor facilities are built and the area restored to good health, everyone will be able to enjoy it," he said.

"Even a short walk in the Gardens of Stone is a visual feast of gnarled gums and wildflower displays set amongst ironstone pagoda sculptures."

Lithgow local Julie Favell, the Natural Areas/Renewables Transition Officer of the Lithgow Environment Group, said she was humbled and overjoyed with the long awaited reservation.

"With acknowledgment for the reserves unique geomorphic and biodiverse landscapes with hidden mysteries still being found today, everyone will be able to enjoy it," she said.

"Ancient cultural stories written thousands of years ago with a multitude of Endangered Ecological Communities, new discoveries presenting to this day with native flora and fauna species.

"A multitude of economic sustainable opportunities await Lithgow to showcase and embark upon a brand new pathway into the future."

Director of the Blue Mountains World Heritage Institute and member of the National Geotourism Strategy working group, Sarah Terkes, said it was wonderful to see the area finally getting the protection and recognition it deserves.

READ MORE: Lithgow residents to breathe easy after waste to energy project scrapped

"The Gardens of Stone State Conservation Area contains all of the outstanding natural and cultural values of the adjacent Greater Blue Mountains World Heritage area - and then some," she said.

"The next step is to realise the potential for this area to become a globally recognised Geotourism destination while ensuring that visitation is managed in-line with protecting the values of the area, including Aboriginal sites, ancient rock art and many rare and threatened species."

Our journalists work hard to provide local, up-to-date news to the community. This is how you can continue to access our trusted content: