"Cancun is the single most heavily-visited vacation destination in Mexico today. And with reason. Magnificent beaches of fine white sand, superb restaurants and lodgings, crafts-and- clothing-shops, history-and-nature-featuring theme parks, and nearby Mayan sites (especially Tulum and Chichen-Itza) of breath-catching interest. Add the same facilities and attractions of the beach-lined Caribbean coast north and south of Cancun (Isla Mujeres, the 'Maya...