south australia’s sub-terranean worlds

From subterranean Edens to volcanic crater lakes, South Australia’s Mount Gambier region has an abundance of ancient underground worlds to explore. Established on the stolen lands of the Boandik people, Mount Gambier sits on the side of a dormant volcano whose last eruption 5000 years ago left behind the magnificent geological wonders unique to the region. According to Aboriginal Dreamtime, the craters were the work of the giant Craitbul; every time he lit a campfire, it was doused by emerging underground water, leaving gaping holes in the ground.

Blue Lake

This cobalt gem nestled in one of the largest volcanic craters is simply breathtaking and is one of the most visited spots in the area. The allure of Blue Lake stems from its mysterious yearly colour change that shifts from a sombre steel blue to a vibrant turquoise almost overnight early each November and remains so until late February. Some experts attribute this phenomenon to the presence of microscopic calcite crystals which scatter the light as it hits the water. The track around the lake stretches 3.6km and stops at view platforms dotted around the crater rim. Grab an early coffee on a chilly winters morning and watch the light and mist dance over the water as the sun rises.

Little Blue Lake

Close your eyes and jump. Feel the tingling rush of the cool water as you submerge yourself beneath the surface of a natural underground lake. The Little Blue Lake is a naturally occurring water-filled sinkhole located 11km south of Mt Gambier stretching the length of 40m across with a maximum depth of 47m. The fully encompassing cliffs sit at a height of 8m above water level however the lake can be easily accessed via a staircase and a floating pontoon.

The Sunken Garden - Umpherston Sinkhole

There is something other-worldly about a secret garden below the earth’s surface. A subterranean Eden of lush green plant life surrounded by sedimentary cliffs draped in waterfalls of vines. The Umpherston Sinkhole originated as a cave then formed through the dissolution of the limestone collapsing the roof of the chamber downwards. The topsoil that fell into the sinkhole formed the perfect environment for a sub-terranean garden. Appreciate from viewing platforms above then venture down the paths provided to fully immerse yourself in this breathtaking wonder. The sinkhole is open at all times and from dusk resident possums emerge into the garden enjoy a fruity feed.

Ewens Ponds

Snorkel above underwater ranges and meadows at Ewens Ponds just south of Mount Gambier. These three spring-fed limestone ponds have a depth of approximately 10m and are connected by a network of shallow channels. Scuba dive into the depths of the crystal-clear waters to find fully submerged ecosystems alive with plants and wildlife. Some of the flora found here cannot be found growing underwater anywhere else in the world.

Kilsby Sinkhole

In the fields of a family-owned farm lays one of the best sinkhole dive sites in the world. 15 minutes outside of Mount Gambier, Kilsby Sinkhole is one of the only of its kind welcoming visitors to explore the depths of crystal-clear water illuminated by beams of sunlight providing incredible visibility. The sink hole was once used as a training facility for SA police and as a centre for weapons research. Snorkel tours of the limestone sinkhole are available to everyone who books - no prior experienced required, as well as scuba dives for certified open water divers.