Right in the heart of the city centre, the Cave Garden occupies a large natural sinkhole that collapsed into the limestone bedrock below Commercial Street. What could have been an obstacle to urban development became instead one of Mount Gambier's most distinctive public spaces: the walls of the crater descend about 15 metres, draped in ferns and creepers, while the garden below is planted with subtropical species that thrive in the sheltered, humid microclimate.
Viewing platforms around the lip of the sinkhole let you look down into the greenery, and steps lead into the crater itself. At night the garden is lit dramatically and the effect is even more theatrical. The sinkhole connects to the underground cave system that runs beneath much of the city.
The Boandik name for the site is Thugi. It is free to enter and open year-round, and sits directly on the main shopping strip — easy to combine with a walk through the town centre.