We recently found an enchanting little park next to the Yarra River in Lower Templestowe in Finns Reserve, Wombat Park. (Melways reference PG33 B4).
Here you will find a wooden maze and flying fox in amongst other swings, slides and sandpits. There are also a few sculptures and a sun dial to make it interesting. Plenty of space for the perfect picnic and all set in a secret garden.
You could go for a walk up to the walk bridge not far up the river and if you are lucky, you may see some native wild life. Or simply throw some rocks in the water - just like Huckleberry Finn!
This park is for kids young and old (even I like to get on a flying fox). It's worth the trip and since finding it we have been back a couple of times.