2. Dive the Great Maya Reef
The Riviera Maya’s nearshore waters include part of the splendid northern swath of the Mesoamerican Barrier Reef System, the Great Maya Reef, which stretches from Isla Contoy southward to the Bay Islands of Honduras. Perhaps the premier natural wonder of the Caribbean, the Great Maya Reef is the Western Hemisphere’s largest reef and the world's second longest, after the Great Barrier Reef of Australia. The banks and walls composed of many dozens of species of coral are centerpieces, but the broader reef complex also includes underwater “lawns” of seagrass, productive mangrove swamps, sandy and coralline cays, and other tropical ecosystems.
This is one of the world's best places to dive, and many tour companies offer guided scuba expeditions, some of which include the reef-scapes of the Isla Cozumel Biosphere Reserve in and around the island of Cozumel. The possibilities of seeing underwater life—from wrasses, groupers, spotted eagle rays, and Caribbean reef sharks to sea turtles, West Indian manatees, and several kinds of dolphin—abound.