The beauty of the Umpherston Sinkhole, also known as the sunken gardens, 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. A large undercover shelter with group seating and free barbecue is provided. Kiosk on site for coffee, snacks, ice creams and souvenirs. Free Entry. Jubilee Highway East Mount Gambier.