Govetts Leap to Acacia Flat has been referred to as the "Duke of Edinburgh highway", and on November 6 it became part of a commemorative national trail.
The 6km walk in Blackheath is one of the most popular trails undertaken by Duke of Edinburgh participants, and this week it was named as part of the 60km, 10-walk National Trail launched for the Duke of Edinburgh's International Award's 60th anniversary.
Descending into the Grose Valley via Rodriguez Pass and Junction Rock, the trail joins the likes of the Coastal Track in the Royal National Park, The Bibbulmun Track in WA, TableTop Track in the NT, and the Dove Lake/Cradle Mountain Trail in Tasmania, on The National Trail.
NPWS Grose Valley ranger Grant Purcell said every week, two Duke of Ed groups of 15-20 participants were walking into the Grose Valley, with groups coming from as far away as Newcastle.
"It's by far the most popular place to do the Duke of Ed. Probably because of the campsite and it's close to Sydney," Mr Purcell said.
"The Grose Valley is breathtaking. It's got millions of years of geology on show."
Katoomba High School student William Corlett walked the trail for his bronze medallion, the first level of the Duke of Edinburgh award. He's also been trail running, reading, and handing out flyers before Western Sydney Wanderers games.
The Duke of Ed award empowers young Australians aged 14-24 to explore their full potential and find their purpose, passion and place in the world. To earn an award, participants must learn a skill, improve their physical wellbeing, volunteer in their community and experience a team adventure in a new environment.
"It's great doing all these hikes 'cause then I can go back and do it on my own. I've done runs on my own - I have more confidence to read maps and find my way," William said.
Katoomba High outdoor education teacher and Duke of Ed co-ordinator, Morgan Huxley, said the program was character building.
"Through completing their awards students have demonstrated resilience, adversity in tough situations and strong teamwork in a variety of situations," he said.
A commemorative plaque was unveiled at Govetts Leap, with acting chief executive of the Office of Sport, Karen Jones, describing the trail as a "Duke of Edinburgh highway."
"The NSW Office of Sport has a proud 20-year relationship with the Duke of Edinburgh's International Award, delivering the program to young people across NSW," she said.
"The 60th Anniversary National Trail is a fantastic initiative which will encourage more young Australians to appreciate our environment and develop a sense of adventure and discovery."
Students from Penrith High School and Barker College also attended the launch.