Playa del Carmen

Playa del Carmen needs 3 days: Quinta Avenida, a 5-km pedestrian strip with shops, bars and restaurants, on one, a full day of diving or snorkeling in Cozumel, 45 minutes away by ferry, on another, and the Xcaret eco-archaeological park on the third. November-April is the dry season. It's mid-to-high priced, more expensive than Tulum in lodging but with a wider price range. It went from a fishing village of under a thousand people in the 1990s to one of Mexico's fastest-growing cities, driven almost entirely by Riviera Maya tourism, and it's the usual base for diving the world's second-largest coral reef, which runs parallel to the coast all the way to Belize.