Crystal pier is gorgeous any time of day! Theres a bunch of coffee shops along the boardwalk and bars/restaurants if you looking for a mid day pick me up or a cocktail its a great place to visit!
Balboa park is iconic with tons of museums, numerous beautiful gardens and the world-famous San Diego Zoo right next door
We live 10 mins from the Safari definately a more relaxed zoo venture :)
The hotel del Coronado is famous and gorgeous just to walk around the grounds/beach and take in the history!