Is there an area that would work for a large gathering of 100+ people?
Yes there is but in that area parking is not the easiest. I do believe there is a parking garage between Ocean Drive and Collins Avenue and if you are planning to barbecue, I suggest you check with the city first what you are allowed to do. Same for bringing alcoholic beverages in coolers as I have seen some people receive tickets by beach patrol.
Yes. But you will need a police permit to gather. Many places in the park. It stretches for over a mile.
On street parking with meters and a parking garage nearby.
You can Google the park and see there are wide open green spaces. It would be smart to ask permission for a large gathering from local authorities. There aren't picnic shelters or grills but it's heavily shaded. Also there is a homeless presence sleeping under the trees and panhandling.
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