Maresias

Long beach with the mountains standing right behind it and water warm enough to stay in until you are bored. Stayed at a friend's place on the sand with a pool and a lawn running down to it, which is the way to do this - the sunset from the grass with the palms in front of it was as good as anything on the beach itself. It is a few hours out of São Paulo, so treat it as a weekend rather than a day.