San Diego has one of the best Zoo's in the country! If you are making this a vacation, this is a must see. The main Zoo is downtown San Diego in Balboa Park but we loved the San Diego Safari Park location that is north in Escondido.
If you want to jump into the famous SoCal water activites while you're here, La Jolla is the place to be. You can kayak, snorkle, surf, stand-up-paddle board or just lay on the beach or visit the Sea Lions. La Jolla is about 25 minutes south of Encinitas.