||A long, narrow coral reef, roughly parallel to the shore and separated from it by
a lagoon of considerable depth and width. This reef may enclose a volcanic island
(either wholly or in part), or it may lie a great distance from a continental coast
(such as the Great Barrier Reef). Generally, barrier reefs follow the coasts for long
distances—often with short interruptions that are called passes or channels. Three
principle examples of this type of feature are Australia's Great Barrier Reef, the
New Caledonia Barrier Reef, and the Meso-American Barrier Reef system—although similar
features exist elsewhere.