The spectacular coastline of Mexico's Yucatan peninsula is a diverse playground where you can bask on pristine beaches, explore ancient ruins, play golf or tennis, go biking, snorkeling or scuba diving, do serious shopping, or escape to a secluded lagoon. With info on Cancun, Isla Mujeres, Cozumel, Playa del Carmen and the Riviera Maya, plus the nearby ruins, this friendly guide gives you the low down on: Everything from unique spa experiences to...