Exploring the Hidden Gems of South Australia’s Limestone Coast


For Graham Kilsby, the sinkhole on his family’s property south of Mount Gambier has been more than just a geological formation—it’s been his playground since he was a teenager.

A man stands in front of the opening of an underwater cave

“I still joke… when we were 12 and above, Mum probably didn’t know quite where we were, but we were here exploring and climbing into the sinkhole when we could,” he said.

About a decade ago, Kilsby decided to share his childhood playground with the world by opening it up as a tourist attraction, drawing visitors from interstate and overseas to South Australia’s Limestone Coast.

Blues and greens of an underwater cave

Underwater Wonderland

“People travel from all over the world to dive in the middle of roads, on farms, and in pine forests along SA’s Limestone Coast. Most of us don’t know it’s there,” Kilsby explains. “We are the capital of sinkholes.”

The region’s abundance of sinkholes, formed by limestone and ancient volcanic activity, serves as a unique drawcard. Kilsby saw an opportunity to showcase not only the sinkholes but also the diverse offerings of the area, including wineries, the Glenelg River, and delectable seafood.

A large shed sits on the edge of a large sinkhole, a natural hole in the ground made of limestone walls.

Growing Attractions

Initially, Kilsby’s decision to turn the sinkhole into a tourism business was driven by practicality—covering insurance costs. But as word spread, interest in the site grew steadily. Tours were soon fully booked during peak seasons, prompting Kilsby to expand offerings to include open-water diving, freediving, snorkeling tours, and even a gin distillery and accommodation.

“We’re getting people from all around Australia coming to Mount Gambier, but we’re also getting that international market as well,” Kilsby says.

Earlier this year, families on a trip from interstate landed four helicopters at Kilsby’s property for a snorkeling tour, highlighting the growing appeal of the site.

Unique Geology

Kilsby’s sinkhole is just one of nearly 20 diveable sites in the region, including Hell’s Hole, Tank Cave near Tantanoola, and the Little Blue Lake, which is also open for swimmers.

Grant Pearce, the Cave Divers Association of Australia national director, emphasizes the region’s unique accessibility for cave divers and the pristine conditions offered by the clear waters and white limestone walls.

Regional Drawcards

As the Limestone Coast’s sinkholes become better known, there’s an opportunity to attract visitors to experience the region’s other offerings.

“A lot of people just want to know where they are. When people come here for our sinkholes and our caves, the benefits and the flow-on of those people coming to this region are incredible,” Kilsby says.

Mr. Pearce sees an opportunity for South Australia to promote the uniqueness of its limestone landscape to both domestic and overseas visitors.

With its hidden treasures waiting to be explored, South Australia’s Limestone Coast invites adventurers to delve into its underground wonders and discover the magic of this unique landscape.