Emergency services were called to the remote site about 10.30am on Sunday, and found a man believed to be in his mid-20s with cuts to his chest and head injuries.

Paramedics first arrived on foot to treat the man, before an ambulance helicopter winched him aboard and flew him to St George Hospital, where he remained in a critical condition on Sunday afternoon.

It is understood the man diverted off a main track and was trying to walk along a cliff rock ledge in a cove close to the Figure Eight Pools, when he fell onto rocks.

Peter Pearce, the secretary of the nearby Burning Palms Surf Lifesaving Club, said visitors sometimes used the cliff as a shortcut during the four-hour hike to get to the rock pools.

"You have to walk around the cove to get to the figure eight pools. Some people use the rock ledge as a shortcut ... but they shouldn't use it - it's very dangerous," Mr Pearce said.

Mr Pearce said the man was in a "pretty bad condition" when emergency services arrived.

Just an hour before the man fell, NSW National Parks and Wildlife Service put out an alert warning visitors that it was "unsafe" to visit the Figure Eight Pools on Sunday, as "waves are likely to wash across the platforms".

The warning, declaring there was a "moderate risk" of visiting the park on Sunday, stated it was "difficult to see the pools in these conditions".

Promoted on social media, the pools are notorious for being dangerous, as waves are known to crash over the site unexpectedly, even in good conditions.

In 2016, 70 people were injured by a freak wave on a single day, with three having to be flown to safety due to the severity of their injuries. There were also a number of other accidents at the site last year, including two men who had to be flown out in July.

Mr Pearce said injuries at the popular natural formation remain common. The remote location added to the danger.

"They have put up signs along the track [to the rock pools], but people just ignore them - especially people from overseas, as it's on their bucket list to visit," Mr Pearce said.

"The signs show pictures of how the conditions should be, and say not to come if it doesn't look like [the pictures], but people just ignore them.

"Next minute a wave washes across the rocks, and we have to treat a lot of them."

On a website outlining daily conditions at the pools, NSW National Parks and Wildlife Service strongly warns visitors to avoid the site, and describes the rock platform as "extremely hazardous".

The walk to and from the site is described as a "steep, rocky and slippery walk in parts and suitable for experienced walkers with a good level of fitness".

The site features phrases such as "people often get dragged across the rocks by freak waves" and "instead of breaking a limb at Figure 8, try some other beautiful places to snap a selfie" as well as the warning "you think it can't happen to you?".

An interactive safety checklist titled "Are you still going to go?" at the bottom of the page takes visitors through all the things they will need to do before going, including checking the tides and packing a first aid kit.