POR actually has a very nice playground. CBR has playgrounds on the beach.
BUT, if you want an all-out playground, there's nothing better than the playgrounds at AK (Boneyard) and MGM (Honey, I Shrunk the Kids Movie Set).
In AK's Boneyard, they can dig for dinosaur bones, and then make their way into the play area with slides, caves, etc.
In MGM's Movie Set, it's just as much fun, but I find it harder to keep track of just where DS is!
That being said, there are CM's posted at the entrances, so no children can just leave by themselves. Just make sure you have a firm hold!