Oceanic swells march relentlessly towards the shallows of Discovery Bay, near Port MacDonnell. As they near the beach they rise suddenly then peel away flawlessly to the left, aided by a savage offshore wind. Amazingly, just two surfers are making the most of it, riding wave after wave while my wife and I watch from the battered shoreline along South Australia’s uncrowded Limestone Coast.
“You want to go out, don’t you?” Michelle asks. “I’d love to,” I reply. “But not today. Today is Sinkhole Day.”
At first glance, the rolling farmlands in the state’s south-east appear benign until you learn how volatile this region once was. About two million years ago, a series of volcanic eruptions started taking place in a region still drowned by seawater. As the oceans slowly retreated, its limestone seabed became exposed until eventually a huge underground system of fresh water seeped through cracks and fissures in the rock, leaving behind the countless sinkholes and crater lakes that we can see today.
Unrivalled as the region’s poster boy is Blue Lake in Mount Gambier. For much of the year, the crater lake appears grey and bleak, reflecting the stormy skies blowing over this part of the country during its long winters. But for several months over summer its colour miraculously transforms into a vivid shade of blue.
Just over a rise is another crater lake that isn’t nearly as fickle. While it may not be as pretty either, Valley Lake is more amenable, fringed by parks and gardens generously populated with picnic benches and barbecue facilities. There’s an adventure playground for kids and an 18-hole disc golf course that’s great family fun (discs are available for free from the Visitors Centre on the Jubilee Highway). Plus, there’s a wildlife park housing kangaroos, emus and koalas that doesn’t cost a cent to enter.
In town, Mount Gambier’s impeccably neat streets and parks have been built around gaping holes in the ground. The Cave Gardens are in the centre, next to the library, and the Umpherston Sinkhole is a magnificent sunken garden that was initially developed by a retired farmer in the 1880s as a cool summer retreat. At the time, visitors skimmed across a natural pond in rowboats, and walkways were cut from the rock.
Michelle and I, with our son Finn, have driven across from Melbourne with the noble intention of discovering everything the Limestone Coast has to offer. Rather than reserving a grass plot in one of the region’s caravan parks, we’ve opted to wild camp in national parks and reserves, booking sites in the coastal dunes beneath the Cape Banks Lighthouse in Canunda National Park, 35 kilometres southwest of Mount Gambier, and then later in the Little Dip Conservation Park outside Robe. Both are commutable distances from the various attractions we plan on visiting during our weeklong stay.
From our Canunda base, we set aside an afternoon in the Coonawarra wine region, a 30-minute drive north of Mount Gambier. Thirty-four wineries cram into a slender, cigar-shaped strip of land that’s famed for rich, red soils that are ideal for growing cabernet sauvignon varietal grapes. Stretching for just 20 kilometres long by two kilometres wide, it is the most densely populated wine region in Australia. Cellar doors include pioneering brands such as Wynns, Brand’s Laira and Hollick.
Further north, Naracoorte Caves – South Australia’s only UNESCO World Heritage-listed site – contain Australia’s largest, most diverse and best-preserved collection of fossil deposits. More than 130 species of animals have been identified here, including extinct megafauna such as giant kangaroos and echidnas, or diplotodons as big as rhinoceroses. Most simply fell into the caves and were unable to escape.
Five caves are open to visitors, often as part of ranger-guided tours. The highlight is Victoria Fossil Cave, where some of the fossils are close to half a million years old. Bats populate other caves and novice spelunkers can try adventure caving.
In Robe, we follow the heritage route through the streets of one of the country’s best-preserved 19th-century port towns, learning about the origins of the cottages and stores that now serve as holiday accommodation, restaurants or wine bars. At dusk, we watch the sun set over The Obelisk at Cape Dombey. And after navigating a path across the tidal sands of Long Beach in our four-wheel drive one morning, I slip on my wetsuit to catch a few waves directly out the front of the Third Ramp boat launch.
We stop in the seaside towns of Beachport and Southend, where sharp headlands protect these summer getaways from the gnashing ocean waves at opposite ends of Rivoli Bay. Holidaymakers in swimming trunks brave driving rains to float atop the salty Pools of Siloam in Beachport and we hike out onto its pier.
There’s plenty to see and do, but it’s the novelty of swimming in sinkholes that intrigues us the most. It’s been more than 20 years since I last visited this region with a mate and ‘Sinkhole Day’ is the one I’ve been anticipating more than any other.
Back then, I donned a mask and snorkel to float through Piccaninnie Ponds, close to the Victorian border town of Nelson. I remember marvelling at its gin-clear water as I drifted above the unfathomable depths of The Chasm. I spotted short-finned eels slithering between aquatic reeds and schools of pygmy perch passed by my nose. This time I do the same, but with my family as company.
I also reserve an hour-long time slot for us to snorkel through Ewens Ponds, where the visibility is even better and the underwater terrain more varied. For 40 minutes or so, the three of us drift along channels that connect a trio of spring-fed ponds.
Just one sinkhole remains on our agenda. After hiking up Mount Schank, our nation’s newest volcano, we drive up the road to Little Blue Lake – a natural rock hole with a picturesque setting and intimate dimensions.
Finn imagines snorkelling around the edges and launching himself into the water from lofty rock ledges. Plunging to depths of 25 metres at its shallowest, there’s no chance of hitting the bottom. But as the day draws to an end, a storm front causes the temperature to dip, making it too cool for us to swim.
“We’ll have to come back in summer,” suggests Finn.
Sounds good to me.
Take me there
Fly: Rex Airlines and Qantas Link connect Mount Gambier with Adelaide or Melbourne on direct flights several times a week. Airfares start at $129.
Stay: There are six campgrounds in Canunda National Park and four in Little Dip Conservation Park. Some are accessible only by four-wheel drive. Campsites cost $16.50 per night.
Swim: Permits are required to snorkel and dive at Piccaninnie Ponds and Ewens Ponds. One-hour time slots cost $15.50 for snorkelling or $51.50 for diving.
Caves: Entry fees to Naracoorte Caves start at $6.50, varying from one cave to the next.
Explore more: limestonecoastvisitorguide.com.au