The Southern Loop at Wilsons Promontory https://parkweb.vic.gov.au/explore/parks/wilsons-promontory-national-park
I completed the hike in four days and it is 60 kilometres. After my first 100 kilometre hike in February this year on the Great Ocean Walk I learned a lot and changed my equipment and Worked hard on my fitness.
This time being over ten kilograms less in body weight and dumping 7 -8 kilograms less in my pack the experience was totally different. The pack in the picture below is Aarn https://www.aarnpacks.com/#!page-4/cfvg
Not trying to sell this pack. However, it is awesome in my opinion, the pockets at the front balance things and allowed me to carry 4 litres of water easily. Also, my daily snacks where accessible.
I have L4 & L5 degenerative discs but thanks to my ongoing strength training and great posture and dedication to well being I can participate and achieve such physical challenges. In terms, of mental health and sleeping in the bush, plus physical exercise often exhaustion, it has a calming effect on me.