A UNESCO Biosphere Reserve, Isla de Cozumel, the largest Mexican island (about 800 km2) located off the coast from Playa del Carmen, is an understandably popular tourist destination. Its superb beaches are well adapted to a variety of activities, in particular scuba diving. Palancar reef at its southern tip is in fact the second largest dive site in the world. San Miguel de Cozumel, the island's only town, is a pleasant place for a stroll after all the tourists have left.