Umpherston Sinkhole in Mount Gambier, SA: Possums in the Sunken Garden
The Umpherston Sinkhole in Mount Gambier, South Australia, is a cenote – a cave with a collapsed roof. It’s now home to the Sunken Garden, a delightfully weird park renowned for its possum colony.
The Umpherston Sinkhole is one of South Australia’s stranger attractions. By the Jubilee Highway as you arrive in Mount Gambier, SA’s second largest city, on the drive from Melbourne to Adelaide, this is nature gone weird.
What is the Umpherston Sinkhole?
Also known as the Sunken Garden, the Umpherston Sinkhole is a cenote. As anyone who has been to Mexico’s Yucatan Peninsula will probably know, a cenote is like a cave cavern, turned through 90 degrees.
The Umpherston Sinkhole was formed when the roof of a cave chamber collapsed. The cave, formed through the dissolution of the limestone that gives the Limestone Coast its name, is now open from the top.
The weirdest garden in Mount Gambier
Over time, however, topsoil has formed in the section of the cave the collapsed roof no longer covers. In 1886 James Umpherston decided to turn it into a garden.
So now there are billowing plants and flower beds at the bottom of the cave, dotted with sculptures and surrounded by hanging vines.
Getting to the Umpherston Sinkhole
There are viewing platforms around the Umpherston Sinkhole, and steps down into the garden.
Once there, there’s a picnic shelter and free barbecue. Alas, there’s no wheelchair access into the garden.
Umpherston Sinkhole possums
The best time to visit the Umpherston Sinkhole is dusk, when a resident colony of possums comes out to play. Or, rather, eat. Feeding the Umpherston Sinkhole possums fresh fruit is something of a Mount Gambier ritual.
Other underground Limestone Coast attractions include the Kilsby Sinkhole, Little Blue Lake and the Tantanoola Caves.
Top Mount Gambier accommodation choices
The best places to stay in Mount Gambier are:
- For something fun and unusual: Old Mount Gambier Gaol.
- For 19th century charm and grandeur: Colhurst House.
- For a good quality motel with low prices: Blue Lake Motel.
- For studio apartments with kitchenettes, washing machines & tumble dryers: Aloha Central Premium Studios.
More South Australia travel
Camp by the Murray River in South Australia at the Mannum caravan park in Mannum.
Stay by the lake at the Lake Bonney caravan park in Barmera.
Eat German feasts at the Hahndorf Inn in the Adelaide Hills.
How long is the drive from Adelaide to Melbourne?
Go on a 4WD tour from Rawnsley Park Station in the Flinders Ranges.