Apex Riverbeach Holiday Park, located along the Murray River is probably one of the best camping spots that we've been thus far.
They offer various type of accommodations to suit everyone, including unpowered sites for the Flintstones' lifestyle (this was what we picked), powered sites, cabins and villas at affordable price. Clean, shared communal bath area and toilets are also available at close proximity.

campsite
Swimming, fishing and boating are the main activities around the park. Catch a murray cod or perch at your own leisure while having a BBQ by the riverside. Well, of course, there are plenty of carps waiting to be fish out too. We had no luck in catching any cod but we managed to catch a family of carps.
Just remember not to throw the carps back into the river as they are considered the river's pest. Or you could hire a kayak or canoe hourly.
Although it is located in the state of Victoria (borderline to New South Wales), the driving distance from Adelaide is actually nearer compared to Melbourne, which makes it a favourite camping/ outdoor spot for many Adelaideans. Therefore, if you're coming from Adelaide, you will be able to cross 3 states (SA, Victoria and NSW) within a day!
Grocery shopping is available right in the township if you forget to bring anything and there are also plenty of cafes along the main street.
Remember to slap on plenty of sunscreen!
Update: Holiday deal for families now available The Family Caravan and Camping Package
Kids stay for free
Get 2 hrs of free wifi per child
Plus 4hrs canoe hire in a 1 or 2 person canoe
To claim this offer, ask for the 'Family Caravan and Camping Package' when you book.
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From 11/1/2013 Until 31/1/2013