Even though nearly all of tourists go to Isla Mujeres, locals choose to visit the more quiet Isla Holbox for per day or two. The island is surrounded by blue waters along with the shallow lagoon separating it with the mainland appeals to migrating flamingos, pelicans and whale sharks (from https://travel-hacks32087.blogrelation.com/34560115/mexico-beach-destinations-no-further-a-mystery