Off-track sites including waterfalls and swimming holes were at risk of becoming notorious social media hot spots like the ones in the Royal National Park, where authorities have been forced to erect fences and issue daily safety alerts due to risk-taking, president of the National Parks Association's Illawarra branch Graham Burgess said.

"We all know what has happened at Figure 8 Pool and Wedding Cake Rock and crowds are now finding their way to a growing number of special places in our region," the NPA Illawarra posted on Facebook.

"The problem for those who manage our parks and reserves is the large number of people who seem to want a high level of thrills and adventure from their bush experiences with little respect for the environment.

"They find places that are challenging and exciting then let all their friends know via social media."

Mr Burgess said sensitive areas were being damaged as visitors "slip down steep slopes, establish highly erodible foot tracks or just take too big a risk to get that selfie".

"The National Parks and Wildlife Service simply can't provide proper tracks to all the sites, even if funding was available ... there are some places that people should just not be going - or not going in large numbers or with inadequate experience."

While the NPA Illawarra visits some of the 'secret' sites, Mr Burgess said these guided walks differed to Facebook meet-ups.

"When bushwalking clubs or knowledgeable and experienced individuals organise walks to adventurous places, as they have done over decades, the structure and policies of the club or group and the leader on the day dictates how the group behaves, what safety concerns there are to be considered, what the impacts on the environment may be and adherence NPWS or other authorities guidelines," he said.

"We encourage people to get out and get active but we want to see all users of social media in reporting on their outings take a step back and think of the implications of what they say can have on our special places."

Jenae Johnston, founder of Bushwalk The 'Gong, which organises group walks and publishes guides, said she always takes safety and the environment into account.

She said the answer to the problem was increased spending on infrastructure in our national parks and a greater local presence online from the NPWS.

"We need to create experiences and provide adequate trails that protect places, but also allow for safety and future population growth."

Illawarra Mercury