My friend had her 4 yr olds bday party today at Robelle Domain Park, Springfield.
Whilst I don't have kids yet I thought the park was great, markets there today, lots of BBQ, and play equipment. ( which apparently has a "water park"- but it was out of order today). Lots for the kids to do
The only downsides are:
1) There is that there is a "lake" that the kids were drawn to
2) retaining walls which can be high for little ones
3) if you don't get an undercover area it is fairly exposed ( I'm quiet sunburnt now)
But if you are prepared ( with sun protection) and keep the kids at the playground then there shouldn't be an issue