Best. Hotel pool. Ever. The Biltmore in Coral Gables. One of the most beautiful hotels I've ever visited. If you're in the area on business during the off season, the rates are surprisingly reasonable.
Venetian Pool (Coral Gables, Florida) It's the city municipal pool! What a great place to visit. But your child must be at least 2 to enter. They didn't believe my baby was 2 (she was small), so I held her up to the window and had her recite the alphabet! They let her in.