We're (me + girlfriend, 25-30 yrs) going on a holiday to the U.S. at the end of July. We're flying from Mexico to Miami and have 4-5 days before flying back to Europe. How would you spend it? We'd like to do some shopping and maybe a dive or two. I also enjoy taking photos. What do you recommend (national parks? Key West? water parks? other things?)? We might also rent a car.. All the help is highly appreciated!