Patty Civalleri, author of the upcoming book “Florence: A Traveler’s Guide to Its Gems and Giants,” will discuss her favorite historical, architectural and artistic spots in the city. Watch a slide show, then explore the tide pools at Point Fermin on a walk led by staff from the Cabrillo Marine Aquarium When, where: 1-2:30 p.m. Saturday and 3-4:30 p.m. March 12. John M. Olguin Auditorium, Cabrillo Marine Aquarium, 3720 Stephen M. White Drive, San Pedro.