We are scheduled to visit Cancun in early December for 4 nights and then will be moving to a resort in Akumal. We have visited Akumal, Playa and Cozumel many times but have decided a few nights in Cancun are in order. We have booked a private condo on the hotel zone but noww need some suggestions on what to do/see. We like to snorkel, walk, swim, fish - are not big nighttime partiers by any means. Any suggestions - all input greatly appreciated.