Golden Gate Park Activities
San Francisco Botanical Garden
1199 9th Ave., Golden Gate Park
When you visit the De Young Museum in Golden Gate Park, it's also worth a stop at San Francisco's Botanical Gardens. They have a beautiful area featuring native California plants, but you can also find a significant Magnolia collection, an Andean cloud forest, and (to satisfy your inner landscape designer) a crazy-good succulent garden.
California Academy of Science
55 Music Concourse Dr., Golden Gate Park
This is an incredibly rich and well-staffed resource for everything science-related, from informative exhibits on the future of our planet, to an incredible planetarium, to a scaled-down rainforest complete with all sorts of live critters. On Thursday nights, they do a really fun adults-only party with numerous bars and amazing guest DJs.