Dog Experts have long counseled that a tired dog is a happy dog, and a tired happy dog is far less likely to get in trouble at home. A dog park gives animals a chance to let off steam. It provides a spacious area for dogs to play and be socialized with people, as well as with other animals.
Dog Park Factoid
For those of you who would like to get a little exercise in with your dog, here's a factoid: one lap inside the dog park equals .16 of a mile. Make 6 laps and you've got .96 of a mile. A side benefit is that this also keeps the dogs moving and minimizes the tendency for them to gather in packs.