'Risking my life': new fence to stop selfies at Wedding Cake Rock

It's the potentially fatal social media phenomenon that no amount of common sense seems to be able to stop.

Wedding Cake Rock, in the Royal National Park south of Sydney, is a white sandstone rock ledge perched precariously on the edge of the ocean.

But despite a 1.6 metre high fence, large warning signs and threats of $3300 fines, thousands of social media users continue to put their lives at risk by taking photos at the site.

Now, the National Parks and Wildlife Service have admitted defeat, and have revealed they have been forced to build an even bigger fence.

"We are looking at a variety of fencing designs and materials, at an additional cost to taxpayers, in an effort to deter those who are disobeying warning signs and climbing over the fence," a NPWS spokeswoman said.

"We are assessing fence designs which are proven to be more difficult to climb, using more robust materials, whilst retaining a similar fence height. The new fence will be installed next year."

NPWS had issued 13 on-the-spot $300 fines since April 2016, with numerous other verbal cautions issued, she said.

"Nobody wants a national park filled with obtrusive fences and signs but the irresponsible behaviour of those putting many at risk have left NPWS with little choice."

In 2015 The NPWS engaged a geotechnical survey using a drone which found Wedding Cake Rock was unstable and could collapse at any time, as early as the next 10 years.

But as a quick look at Instagram reveals, thousands of people are ignoring the signs and jumping the fence to get a selfie on the edge of the rock. There were more than 25,000 posts tagged #weddingcakerock. One user posted a photo of herself with feet dangling over the edge captioned "Risking my life for this."

"We are calling on people to think about the consequences of their actions, the impact an accident would have on themselves, their family and friends and the emergency services people who put their lives at risk to undertake dangerous cliff rescues and retrievals," the NPWS spokeswoman said.

The rock formation forms part of the Coast Track, a popular two day walk from the village of Bundeena to Otford. But in recent years, the majority of foot traffic has been focused on Wedding Cake Rock. According to the NPWS, on a busy weekend, around 1500 people visit Wedding Cake Rock. About 80,000 people walk the Coast Track each year.

French student Fabien Ardio died on the site in 2014 when a section of the cliff gave way.

In November 2015 two men were rescued after one fell from the rock and landed on a precarious ledge metres below.

Shazia Edah-Tally, 19, fell to her death further north on the coast track between Bundeena and Wedding Cake Rock in April 2017.