Allen Gardens is a nice little dog park to take your dogs too if you live downtown. Unfortunately for me, I don't--so I have visited this place only about 3-4x.
It's not so much a dog park as a sandy, gritty area split into two for small dogs, and large dogs. It IS gated though, which is very safe--especially considering you are downtown. It is pretty unremarkable. There is no grass, no agility equipment, nothing but other dogs and owners. There isn't much room for fetch either, so my cattle dog gets bored quite easily.
If you have a very social dog though, this would be a nice spot to visit.