I was there 6+ years ago with my mom and sisters for a "gilrs trip". My sisters have been multiple times since then with their spouses or each other Restaurants we enjoyed (that they returned to on subsequent trips) include the Bubble Room as mentioned above, a place called Matzaluna (sp) featuring italian that was very nice. Also a place called the Hungry Heron which was in a strip mall, frequented by more locals than tourists with an extensive and reasonably priced menu, good food. We tried the popular Mucky Duck at the tip of Captiva...but IMHO the sunset was the attraction as opposed to the food

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We stayed at the Sundial Resort (condos) on Sanibel, my sisters have stayed different times at Casa Ybel on Sanibel and at 'Tween the Waters Inn and also the big place out on Captiva (South Seas Plantation?). These all were right on their own beaches. I would do an internet search to check various places out too!!
Shelling on the beach is the best "activity" IMHO
The Ding Darling Nature preserve was also a highlight for me...but I like that sort of thing...all kinds of birds, waterfowl, gators, etc . It's a huge place, you can just walk around some parts, or bike it or take a more extensive open-air bus tour.
It's a great place for a beach vacation.....a little more laid back than WDW
