The known size of the Engelbrecht Cave system, which runs under the township of Mount Gambier on Boandik Country on SA’s Limestone Coast, has recently doubled, with the discovery of an additional 330m in the east section.


The cave system, which consists of a sinkhole and two major passages, had long been mapped out to extend 300m west and 70m east. Until 2019, when divers Josh Richards and Matthew Aisbett discovered a new section of dry caves, after receiving a tip from another diver and seeing a reflection on the roof of the cave.

‘It wasn’t on any of the maps, so we doubted anybody knew about it,’ Josh told ABC News.

But the big breakthrough discovery of the depth of the east section extension, didn’t come until mid-2021. 



While diving, Josh noticed a silt stream moving in an unexpected direction and dove down to follow it. He found himself face to face with a ‘gaping tunnel’ that he and his diving team hadn’t ever noticed before. 

‘It kept going and it went vertical into a chimney, when we got to the top it opened up into this enormous room,’ Josh told ABC News. 

‘To think this cave that people had been diving and exploring for the last 50 years had this little tunnel at the back that opened up into this enormous cave network — we were mainly in shock the first time we found it,’ he said.

And Josh says there’s certainly more to be discovered, with a ‘spider web’ of branches expected to splay out underneath Mount Gambier – and possibly even a connection to Thugi/Cave Garden, the 30m deep cave in the town.