A landmark in the Royal National Park, south of Sydney, has been cordoned off after a geotechnical assessment showed it is unstable.
According to the report, all or part of Wedding Cake Rock is likely to collapse without warning in the next decade.
The assessment involved a photographic survey of the underlying rock strata using a drone. The resulting drone footage showed that Wedding Cake Rock is precariously balancing on the edge of the cliff and severely undercut.
The vertical fractures that make the rock look like a slice of wedding cake clearly mark where it will eventually give way and tumble to the sea 50m below.
Speaking to Australian Associated Press about the investigation, New South Wales National Parks and Wildlife Service (NPWS) regional manager Gary Dunnett said: “[It’s] given us a really, really clear picture of Wedding Cake Rock, and that is that it is likely to collapse within the next 10 years.”
NPWS carried out the assessment after the landmark started attracting lots of attention from the public, with visitors posing for photographs near the edge.
Dunnett added: “It’s only when we’ve had that extraordinary attention…that it’s become apparent that it’s an unacceptable risk to have people close to the edge.
“We want people to continue to come along and enjoy it, particularly during the whale watching season…but you need to stay back.”
Temporary safety fencing has now been installed, but there are plans to construct permanent viewing platforms.
Watch the NPWS video below for more information about the investigation.