The Blue Lake in Mount Gambier occupies one of the craters of the extinct volcano after which the city has been named.

Early each November, the lake's sombre blue, which is in evidence during the winter months, mysteriously changes to an intense deep turquoise blue almost overnight. The colouring remains until late February, when it gradually changes. From late March, it returns to a distinct sombre blue colouring that remains until the following November.

The 3.6 kilometre road and walking track around the circumference of the Blue Lake provides access to many viewing points, the most popular being the underpass between the Blue Lake and the Leg of Mutton Lake.

Aquifer Tours operate a fascinating 45 minute tour which takes visitors in a glass panelled lift down the original dolomite well shaft, from which water was originally extracted, through a tunnel to see the Blue Lake at close proximity. Learn about the hydrology of Mount Gambier's water supply and the aquifer system. Hear the interesting stories of local history, European settlement, folklore and Aboriginal legend. Daily tours are available, contact the Mount Gambier Visitor Centre for further information.

The crystal clear waters have been slowly filtering through the limestone and forming the Ponds' features over thousands of years. Snorkel across the top of The Chasm and peer down into the dark depths below or dive down into the large underwater cavern known as The Cathedral.

Explore the spectacular underwater world of Piccaninnie Ponds which is recognised as a wetland of international importance.

The freshwater rising to the surface under pressure has eroded a weakness in the limestone to form The Chasm. This same process has formed the large underwater cavern known as The Cathedral creating its majestic white walls of sculptured and scalloped limestone. Be sure to visit the Lower South East Marine Park which also offers plenty of diving experiences.

On land, take a walk along the beach and see the freshwater springs bubbling up onto the sand.

There is also a walking trail through coastal wattle and beard heath to the ponds outlet. On the way, view the southern ocean and the lower south east marine park. The walk then leads inland via boardwalks into silky tea-tree and cutting grass to a lookout where views of the wetland and bamboo reed and bulrush can be seen.

Engelbrecht Cave is one of the Limestone Coasts fascinating cave sites. Inside the cave you will find a viewing platform and much of the cave is accessible to divers. It is a unique cave close to the centre of Mount Gambier. Take a tour to discover why cave divers swim through the water filled passages under the streets and roads of the city. Cafe available selling artisan food and gifts.

Engelbrecht Cave is well worth a visit for both cave divers and for those who simply wish to enjoy the beauty of the caves. Fully guided tours of two caverns are available, lasting between 45 to 60 minutes.

The beauty of the Umpherston Sinkhole has to be seen to be believed. Appreciate its size and depth from the viewing platforms at the top of the sinkhole, then walk down into the sinkhole, along the terraces and behind the hanging vines. The resident colony of possums make an appearance at dusk and enjoy being fed fresh fruit (no bread please). A large undercover shelter with group seating and free barbecue is provided. The kiosk on site offers coffee, snacks, ice creams and souvenirs.

Umpherston Sinkhole, also known, as the sunken garden was once a cave formed through dissolution of the limestone. The sinkhole was created when the top of the chamber collapsed downwards. Now the topsoil down on the floor forms the perfect environment for the sunken garden.

The sinkhole is open at all times and from dusk each evening the area comes alive with possums as they venture into the floodlit gardens to feed.

The geological processes that have created the sinkholes in the region inspired the sculpture at Umpherston.

Serenely located beneath a rural farming property only 15 minutes from Mount Gambier, 'Kilsby Sinkhole' is world-renowned as one of the best sinkhole dive sites due to its crystal clear water and breathtaking visibility.

Kilsby Sinkhole is the only site of its kind that welcomes snorkellers, freedivers and Open Water certified scuba divers under the supervision of a licensed and industry qualified guide.

Kilsby Sinkhole is also home to Sinkhole Gin, produced from crystal clear limestone-filtered water and local native botanicals.

Snorkelling and Sinkhole site tours (incorporating gin tastings) are achievable by prior arrangement only. Instant bookings can be made online.

Scuba and Free diving must be arranged with one of our registered Licensees of the the site ( a list of these are on our website , bookings for these experiences are made though these licensees only.)

All equipment is provided and water activity is completed under the supervision of an industry-certified guide.

Visit South Australia’s only World Heritage listed site and discover one of the world's most important fossil sites. For over 500,000 years giant marsupials such as the wombat-like Diprotodon, Thylacoleo the marsupial lion and giant kangaroos roamed the Limestone Coast, with many of their fossils now on display.

With five different caves to explore, plus adventure caving, photographic tour options, a brand new adventure playground, café, campgrounds and an above-ground accessible loop-walk, Naracoorte Caves offers experiences for everyone.re, where you’ll watch and learn about the resident southern bent-wing bats, a critically endangered species and be able to watch them via infrared camera. The tour then heads into the majestic Blanche Cave.