We lived in San Diego when my kids were toddlers. Some recommendations that I have are as follows: Scripps Aquarium in La Jolla, Torrey Pines state beach, La Jolla shores, Sea World (has bay of play geared toward younger children), Balboa Park (lots of room to run around and has a carousel). There are parks every where in San Diego. I'm not sure of public splash parks. We had one in our neighborhood but it was owned by the HOA and thus not open to the public. The zoo is awesome and we really miss it. Be sure to check out the elephant exhibit as it is relatively new. There is also the Wild Animal Park in Escondido which is part of the San Diego Zoo. You can take a safari ride which my kids always enjoyed. Have a wonderful time!