Anyone interested in nature, animals, conservation or wild life who goes to San Francisco should consider visiting the Marine Mammal Center. It is located at 2000 Bunker Road, Fort Cronkite, Sausalito. That may not help a lot, but you can call them at 415-289-7325 or go to MarineMammalCenter.org. You'll find information there and also driving directions at mapquest.com by using the above address. They have tours at 11 AM, 1 and 3 PM which are $7, $5 for seniors. Admission is free. This is a center in which injured or sick marine mammals, mostly but not exclusively seals and sea lions, are treated and rehabilitated and, when feasible, released back into the wild. It's possible though not easy to get there by public transportation; call them for info. Your best bet is to rent a car for the day in SF, drive there and maybe take a side trip into Sausalito or the wine country, then return the car rather than be burdened with it in the city.