The island is home to the world's second-largest coral reef  and is ringed by some 30 dive sites, most of them concentrated along the west coast. The abundance of reefs plus the transparency of the Caribbean have made  Cozumel a major diving destination.

Cozumel is Mexico's original Caribbean playground. The Maya, its first inhabitants, named it Cuzamil, meaning "Land of the Swallows." However, it  was the goddess of fertility, Ixchel, that they worshiped here and the remains  of centuries old Mayan temples and ceremonial centers still dot the island.

This is where Europeans first stepped on Mexican soil, and a plaque on the beach marks the spot Catholic mass was first celebrated in Mexico. But the Spanish explorers didn't stay. Fresh water was in short supply and the mainland natives  were hostile, so the conquerors pushed on in their search for El Dorado. Cozumel  was largely forgotten, except by pirates, such as Jean Lafitte, who frequented  the island. Popular legend notwithstanding, no buried treasures have been found to date.

During World War II, the U.S. built an air base on Cozumel for planes hunting U-boats in the mid-Atlantic. Drawn by the clear waters, frogmen came to train and returned home with stories of magnificent underwater vistas. After a visit to the island in 1962, oceanographer Jacques Cousteau even  proclaimed Cozumel to be one of the finest diving sites in the world.