Blue Hole

Plummeting into the heart of a volcanic crater, the Blue Hole is one of Australia's most surreal swimming experiences. This crystal-clear, sapphire pool lies within the eroded cone of an extinct volcano near Mount Gambier, its vivid colour and sheer depth (around 80 metres) drawing visitors from across the country. Surrounded by dense manna gum forest and limestone cliffs, the Blue Hole feels both ancient and otherworldly — a place where you can float above an abyss of pure, filtered water. It's a must for anyone exploring the Limestone Coast region.

Highlights & What to See

• Swim in the crater: Descend the steps to the floating pontoon and immerse yourself in the impossibly blue water. The visibility is exceptional, making every stroke feel like you're suspended in liquid glass.
• Observation platform: Before swimming, head to the lookout for a bird's-eye view of the crater's perfect circle and the deep indigo water below — it's a photographer's dream.
• Interpretive signage: Learn about the geological formation of the Blue Hole and its significance to the local Bungandidj people, who have long revered this sacred waterhole.
• Nearby Umpherston Sinkhole: Just a short drive away, this collapsed limestone cave has been transformed into a lush sunken garden, offering a completely different but equally magical landscape.

Suggested Time to Spend

Allocate about 1 to 1.5 hours to fully enjoy the Blue Hole. This gives you time to take in the view from above, change into your swimmers, and spend a leisurely 20–30 minutes swimming in the crater. If you're planning to visit multiple volcanic features in the area (like the Umpherston Sinkhole and Mount Gambier's other craters), half a day is ample to explore them all at a relaxed pace.

Nearby Areas Worth Combining

• Mount Gambier — The regional hub offers excellent cafes, the historic Cave Gardens, and the famous Mount Gambier Blue Lake, which turns a brilliant turquoise each summer.
• Coorong National Park — A stunning coastal lagoon system about 1.5 hours north, perfect for birdwatching, fishing, and spotting pelicans.
• Penola & Coonawarra — Wine lovers shouldn't miss the Coonawarra wine region, known for its world-class cabernet sauvignon, just 30 minutes north of Mount Gambier.
• Naracoorte Caves National Park — A UNESCO World Heritage site featuring fossil-rich limestone caves, about an hour north-east of the Blue Hole.
• Port MacDonnell — This coastal town, 25 minutes south, offers dramatic cliff walks, seal colonies, and the famous 'Penguin Parade' at sunset.

Please check official sources for current details.