Belize Barrier Reef Reserve System

Second only to Australia's in scale, the barrier reef running along the coast of Belize is the largest in the northern hemisphere, and its seven protected areas take in offshore atolls — including the famous Great Blue Hole — hundreds of sand cays, mangrove forests, lagoons and estuaries. Sea turtles, manatees and the American crocodile all depend on the system, which UNESCO inscribed as the Belize Barrier Reef Reserve System in 1996.