If you plan on visiting the San Diego Zoo you are in Balboa Park along with at lease 13 museums. Yes----
All in the same area.
When you check out the site for the San Diego Zoo click on Balboa Park
too. This will bring up at least 13 different interesting museums in the park and what they are, including a park map.
Prices are quoted on many combinations depending upon your wants. Be sure to check them out to insure you get the best value for what you want to see.
The "whole hog" of the 13 museums, Passport to Balboa Parek AND the San Diego Zoo is $65.00 for adults and $36.00 for children, for a seven day pass. Please check to see how they work the passes. I do not know if the zoo allows you to enter on a second day. The seven days start from the day you purchase your tickets, not your first day there. Again, always check the fine print.
Balboa Park has over 1200 luskly planted acres.
Don't forget the other attractions in the San Diego area. I will see if I can update them later for you. Most of the readers have already mentioned them, such as...
Old Town San Diego
San Diego Wild Animal Park
Various (other) museums
Coronado Bridge & Island
For all California Beaches showing beach color photos, hotel and resort listings and other information: California Beaches | Vacation Travel Guide for Beaches in California
Check your hotel, motel or other place of lodging, lobby for pamphlets on other attractions, discounts, special offers, etc. in your area or areas that you are going to visit. Check the ones next to you as they could have other different offers.
Best wishes to you, your family and friends while visiting us. Drive carefully.