Babymoon trip for the older child

This Friday, Alex, Toby and I are taking a much-anticipated trip to San Francisco! We'll be visiting my sister for a week, and we're thinking of it as a babymoon trip for Toby. Since his world will be turned upside down when the baby arrives this summer, we decided to front-load all our vacations this year and take one last trip as a family of three, during which we'll dote on him, have tons of mommy-daddy-Toby time, and do everything he loves most: planes, trains, playgrounds, a million tacos for lunch:)

I'd love to ask: Do you have any family-friendly advice for San Francisco? Any yummy restaurants, ice-cream shops, playgrounds, museums, toy stores, or overall kid-friendly activities? We want to make it really special for Toby and would be grateful for any insider tips. Thank you so much!
P.S. Toby's first trip to San Francisco, and grown-up San Francisco advice.

(Illustration by Kevin Dart; photo by Alan Levine)