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.