While in San Diego:

Beaches: San Diego is home to the most “perfect weather in the U.S.” and has over 70 miles of sandy coastline and warm, clear waters to go with it. A trip to San Diego wouldn’t be complete without stopping to relax at one of these pristine beaches.

San Diego Zoo: This world-famous zoo and research facility is considered one of the best in the country, and is home to over 4,000 rare and exotic animals. Explore habitats in 10 bioclimatic zones, from the arctic tundra to the rainforest.
http://www.sandiegozoo.org