The cayes, the offshore atolls and the barrier reef are one of the main attractions of Belize. The barrier reef, which is 185 miles long, is the longest in the Western Hemisphere. The cayes (pronounced keys) are islands that are located between the mainland and the barrier reef.
Ambergris Caye is the largest of Belize's more than 200 off-shore islands. About 25 miles long and narrow, it resembles from the air a spiny backbone, a vertebrae of land divided by discs of irregular grey mangrove lagoons. About three-quarters of a mile off shore, draped along the beach on the windward side of the island is the longest and most spectacular coral necklace in the Western Hemisphere, the Belize Barrier Reef.
The beach runs more or less parallel to the reef except at a place called Rocky Point, where it reaches out and touches it. Rocky Point is about 4.5 miles south of Boca Bacalar Chico, a partly man-made by Mexocans in 1899 channel which separates the island from the Xcalac Peninsula and forms a portion of Belize's northern border with Mexico. This channel is, for the most part, narrow and shallow. In some spots it shrinks during low-tide to a stream which can be crossed on foot.
The reef is a living wall formed by millions of coral organisms. These corals are carnivorous animals known as polyps, which eat small sea creatures that float by, capturing them with stinging tentacles. Polyps feed only at night, pulling their tentacles back into the skeleton during the day. Within the reef's skeleton live minute blue-green algae. These give off oxygen which the coral polyps breathe; the algae, in turn, absorb the carbon dioxide which the polyps give off, forming thus a genuine symbiotic relationship. Corals are multicoloured varying from gold to red, orange, green, brown and yellow. The soft, living tube-shaped coral polyp protects itself by generating a hard layer of calcium carbonate called the corallite. Colonies of these polyps form the reef structure growing in strange and exotic shapes from which the different varieties of corals take their popular names, such as brain coral, staghorn coral and elkhorn coral.
Ambergris Caye became undisputed superstar of Belize's tourism industry, 'La Isla Bonita' is an enigma that continues to defy the odds by somehow balancing large-scale tourism development with a fun, laid-back atmosphere with San Pedro town as the island's gateway and centre for sailing and reef exploration.