Miami beach regional library at 2100 collins ave is honestly the most comfortable free spot on the beach. Third floor has huge windows facing the ocean and super comfortable chairs.

Free wifi obviously, clean bathrooms, and nobody cares if you doze off in the reading areas. Perfect for escaping the afternoon heat without buying overpriced drinks.

Parking is metered but the building itself is free to hang out in as long as you want. Way better than sweating on the beach all day.