The declaration is a legally recognised mechanism to bolster existing measures that protect the species for future generations.

The NSW Premier, Gladys Berejiklian, said the historic declaration recognises the extraordinary global significance of the Wollemi pines, with some of the adult trees estimated to be up to a thousand years old.

"This declaration enables us to take existing protections up another notch, and set specific legislative requirements including a dedicated fire management strategy to secure the survival of the species for generations to come," Ms Berejiklian said.

"Prior to their discovery in 1994, Wollemi pines were only known to us in fossil records with fossil evidence pointing to the species' existence up to 90 million years ago."

Just over 12 months ago, teams from the RFS and National Parks undertook an extensive operation to protect the Wollemis from extinction when the secret site came under threat from the devastating summer bushfires.

Environment Minister Matt Kean said the site is the first to be declared under new provisions in the National Parks and Wildlife Act that will enhance conservation for the most precious and rare jewels in our national parks crown.

"The Wollemi pines are often described as a living fossil, having been around when dinosaurs roamed the Earth," Mr Kean said.

"Despite the incredible efforts by the NPWS and RFS teams last summer, several hundred juvenile trees in the protected site were impacted and are yet to re-sprout.

"That's why we need to act now to put long-term protections in place that reduce the risk of fire exposure and allow the slow-growing juvenile trees to thrive."

The declaration will allow for special regulations to enhance the pines' legal protection including requiring a dedicated fire management strategy, ecological monitoring and ongoing conservation management.

The Nature Conservation Council welcomed the decision.

NCC acting chief executive, Jacqui Mumford, said: "The creation of Assets of Intergenerational Significance as a new category deserving special protection is a great precedent.

"The Wollemi pine is a critically endangered iconic species that must be conserved at all costs. We hope this new designation will also be applied to the other 100 species in NSW that are listed as critically endangered."

The Wollemi move came as the premier also announced $257 million funding over three years for national parks across the state.

Environment Minister Matt Kean said almost $41 million has been earmarked for new or improved infrastructure projects in the Blue Mountains region alone.

"The Evans Lookout will receive a $1.6 million overhaul including wheelchair access to the lookout so the spectacular views of the Grose Valley can be enjoyed by visitors of all ages and abilities," Mr Kean said.

"Work is also underway along the southern escarpment with NPWS crews and specialist contractors currently constructing the Grand Cliff Top Walk - a $10 million world-class track that will take people along the valley top, waterfalls and cliff edge lookouts between Wentworth Falls and Katoomba and provide an exceptional experience of this World Heritage Area."

The Evans Lookout project includes a new 200m pathway, upgraded seating, picnic facilities and amenities, and is scheduled to be completed by the end of 2022.

Over the past 12 months NPWS has been completing construction works to reopen the region's most popular walking tracks damaged by last summer's bushfires, including the renowned Katoomba to Kanangra walk, the Clifftop Track, Perry's Lookdown and Victoria Falls tracks.

The track between Evans Lookout and Govetts Leap is now open following eight months of construction work by NPWS crews and contractors in extremely difficult terrain.