The fascinating sinkholes in Mount Gambier to visit

Dilvin YasaBy Dilvin Yasa
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Fancy a swim in a dazzling cobalt waterway, or a stroll around a lush, emerald wonderland? The famous Mount Gambier sinkholes can set the mood for every kind of adventure.

Reykjavik, Naples, Cartago; when you’re yearning to explore a dramatic volcanic landscape, there’s only one destination where the sinkholes – a depression caused by the collapse of the surface layer – are a celebration (particularly in the warmer months): Mount Gambier  on South Australia’s spectacular Limestone Coast.

Proving that good things are worth the wait, geologists believe that Mount Gambier’s (justifiably) famous sinkholes are the result of rain on the region’s three fault lines breaking up the huge expanse of limestone, more than 25 million years old, spanning South Australia’s south-east. Water flowing through the limestone has formed 50 sinkholes, with at least 15 of them filled with water.

So, when is the best time to take advantage of Mount Gambier’s sinkholes? While Mount Gambier itself is a treat to visit year-round, aqua babies are best to plan a trip in the warmer months, between November and March, when the water is less biting and the colour morphs from a hue which can fall anywhere from steel grey or garden variety blue to vibrant cobalt. The good news? Whether you hire a car and drive to each spot (easily done since most of the major holes are located within a 20-minute drive of one another) or book a tour, there’s the perfect sinkhole experience for every kind of traveller, including these tourism-heavy hitters.

Kilsby Sinkhole

sunlight shines upon a diver underneath the Kilsby Sinkhole
Kilsby Sinkhole is a naturally occurring karst basin. (Image: Adam Stern)

Will it be snorkelling, scuba diving, free diving or a sinkhole tour of the training site for the South Australian Police? At Kilsby Sinkhole , located on a sheep farm among the rolling grasslands of Moorak just 14 kilometres south of Mount Gambier, you can choose all of the above.

Out here, where it’s not unusual for people to show up in mermaid outfits for the ultimate photoshoot, water clarity has drawn people to the site for decades, the giant chasm descending 65 metres and allowing up to 50 metres (most days) visibility for scuba drivers and freedivers, and pristine water clarity for those who prefer to frolic towards the surface. 50-minute guided tours cover the sinkhole’s fascinating history and geology – a real hit with the kids.

a diver facing the light as it passes through the water under Kilsby Sinkhole
It’s a stunning sight when the sun rises over Kilsby Sinkhole. (Image: Adam Stern)

Snorkelling tours run for two hours, complete with a safety briefing and under the supervision of a snorkel supervisor, while those interested in diving and freediving can book a licensed operator to help their dream come true.

Kilsby Sinkhole is a privately owned site, thus, all visits must be pre-booked online. The good news? They now offer a range of two-bedroom luxury villas at a surprisingly affordable price point, so you can take advantage of the sinkhole (and its surrounds) day after day.

Umpherston Sinkhole

a large crater at Umpherston Sinkhole
Subaquatic flora grows abundantly in Umpherston Sinkhole. (Image: Offroad Images)

In the middle of Mount Gambier’s city streets, a lush, subterranean oasis blooms some 20 metres deep in a natural well providing cool respite for those who want to escape those blazing days, but don’t much fancy getting wet.

Named after its designer James Umpherston who designed this urban botanic garden in the late 1800s, Umpherston Sinkhole/Balumbul (one of the most photographed locations on the Limestone Coast) was once a cave formed through the dissolution of the limestone, becoming a sinkhole only after the top of its chamber collapsed and its topsoil provided the perfect environment on which flora to grow.

lush greenery at Umpherston Sinkhole
Stroll through the enchanting vines. (Image: South Australian Tourism Commission/Adam Bruzzone)

Now it’s best described as a gateway to a secret world filled with hanging vines and terraces, the depth and scale of which is best enjoyed from the viewing platforms before taking a walk down to the bottom to view the hydrangeas (but only after grabbing an ice cream or coffee from the onsite kiosk). Yep, at Umpherston Sinkhole, it’s all about walking and observing.

Beautiful any time of day, locals swear by a visit at dusk when the friendly locals, the Umpherston possums, come out to greet their visitors. Why not stick around and make use of the free barbecue area?

Little Blue Lake 

an aerial view of the Little Blue Lake sinkhole in Mount Gambier
Little Blue Lake is situated within a dormant volcanic crater. (Image: Thomas Cowey)

Disregard its name; Little Blue Lake is actually a sinkhole with a difference: the ability to change colour like a mood ring so that the steel grey it rocks throughout the winter months transforms into a vibrant cobalt blue come the summertime (November to March). It’s all thanks to a phenomenon caused by the formation of calcite crystals warmed by the rays of the sun.

Located in the Kanawinka volcanic area, wedged between the two (mercifully) dormant volcanoes of Mount Gambier and Mount Schank, follow the campervans making a line to Little Blue Lake, which is conveniently situated in a paddock by the highway.

a diving platform above the milky turquoise waters of Little Blue Lake, Mount Gambier
Mount Gambier’s Blue Lake transforms into milky turquoise between November and March. (Image: Lucy Adamopoulos)

With a 47-metre depth, plus a diameter of 40 metres, the lake is what you might call bracing – a fact locals love and visitors quickly get used to as they enter the sinkhole via the stairs or ramp. Your best bet? Warm up beforehand or afterwards by lying out in the sun, or by enjoying a picnic (you’ll have to bring your own provisions). Just beware that there are no public amenities, so best to use the bathroom before you depart from your accommodation.

Got plenty of time in and around Mount Gambier up your sleeve and are keen to experience further sinkholes? Be sure to also put Ewens Ponds, Hell’s Hole and Caroline Sinkhole on your list.

Wanting to explore the rest of Mount Gambier? Follow our guide for awe-inspiring things to do in Mount Gambier.

Dilvin Yasa
Dilvin Yasa is a freelance journalist, author and TV presenter whose travels have taken her from the iceberg graveyards of Antarctica to the roaring rapids of Uganda. Always on the lookout for that next unforgettable meal, wildlife moment or 80s-themed nightclub, she is inexplicably drawn to polar destinations despite detesting the cold.
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Incredible day spas and hot springs to visit in Victoria

    Katie CarlinBy Katie Carlin
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    From geothermal pools and luxury spa sanctuaries, Victoria’s mineral-rich waters and restorative landscapes offer total renewal.

    I pass waving coastal spear-grass and coast saltbush as I follow the curving path through 15 hectares of thoughtfully curated gardens at the Mornington Peninsula’s Alba Thermal Springs & Spa . I hang my robe at the entrance and slip into the first sunken geothermal pool I find – feeling the tension from the 90-minute drive from Melbourne melt away as I watch steam dance across the surface in the late afternoon light. There are 31 pools, a mix of geothermal, cold plunge and botanical, that range in temperature and design, spread over six regions.

    a woman relaxing at Alba Thermal Springs & Spa on the Mornington Peninsula
    Alba Thermal Springs & Spa on the Mornington Peninsula. (Image: Visit Victoria)

    I gravitate toward The Hemisphere, with its dry sauna, steam room, cold plunge and dreamy open-air pool called The Hide. But it’s Alba’s brand-new Sanctuary that really elevates the experience. The five luxurious stand-alone villas and two additional studio rooms opened in June 2025 and feature an indoor fireplace, oversized bathtub with views across the bay, a deck and extensive all-inclusive (minus the cocktails) mini-bar.

    After dining at Alba’s Thyme restaurant, I return to my villa, content to fall asleep early listening to the fire crackle, feeling thoroughly restored. While Alba is one of the newest in the region, it’s certainly not the only place to enjoy a soothing soak. Here are others to book for a wellness weekend.

    Hepburn Bathhouse & Spa

    A woman bathes in the new Hepburn Bathhouse and Spa private bathing room with marble tiled walls
    The marble private bathing room is one of five new designs. (Image: Supplied)

    Nestled in the Daylesford region, Hepburn Bathhouse & Spa has been welcoming guests to its historic bathhouse for 130 years. With a $1.7 million renovation now complete (part of the 21st season of Channel 9’s The Block), find five new private bathing rooms, an apothecary experience where guests blend a custom body scrub and all-new spa treatment menu.

    There are three bathing areas: Bathhouse for communal bathing for all ages, adults-only Sanctuary and a private bathing space for a personalised experience – try the skin-softening Mineral Milk Bath.

    Lake House Daylesford

    the pool at Lake House Daylesford
    The main pool at Lake House Daylesford. (Image: Visit Victoria)

    Inciting deep exhales, the spa at Alla Wolf-Tasker’s iconic Lake House has long been a beacon of wellness in the region. Tucked into the cottage gardens that wind down to the lake’s edge, the spa is beautifully and deliberately cloistered away from guests and diners visiting the celebrated on-site restaurant.

    From Ayurvedic facials and hydrotherapy that makes use of Daylesford’s mineral waters, to cocooning thermal rituals and massage, treatments here promote tranquillity. While a day spa experience is delightful on its own, staying on the property adds a luxe layer to your corporeal renewal, especially if you’re in your own private spa villa.

    Metung Hot Springs

    the Metung Hot Springs' glamping tents by the river
    Glamping tents at Metung Hot Springs. (Image: Emily Godfrey)

    Imagine immersing yourself in a barrel overflowing with geothermal water, all while taking in views of Gippsland Lakes. It’s one of several unique bathing experiences available at Metung Hot Springs .

    There’s also a floating sauna and a Reflexology Walk constructed with carefully placed stones designed to stimulate the acupressure points in your feet as you walk. The 12-hectare site opened in 2022 with three bathing areas – Bathing Ridge, Lagoon Precinct and Hilltop Escarpment – and premium glamping tents that feature king-size beds and private bathing barrels.

    Four more blissful day spas to visit

    Lon Retreat & Spa is an award-winning, adults-only retreat on the Bellarine Peninsula.

    Deep Blue Hotel & Hot Springs features sensory caves and cleansing waterfalls in Warrnambool.

    Peninsula Hot Springs renews with 70 bathing and wellness experiences.

    The Benev is an indulgent spa and luxury accommodation in Beechworth.

    the Peninsula Hot Springs
    Bathe in beautiful surroundings at Peninsula Hot Springs. (Image: Tourism Australia/Harry Pope/Two Palms)