The Great Barrier Reef 

The Great Barrier Reef is the world's longest group of coral reefs. It follows the coast of Australia for about 1,250 miles (2,010 kilometers). The reef consists of small islands of solid coral, patches of coral sand, and submerged coral. Coral is made up of hardened skeletons of water animals called polyps that have died. But billions of live polyps are attached to submerged coral. Living polyps and other animals give undersea parts of the Great Barrier Reef a brilliant coloring. Many people are concerned about possible damage to the reef by the large numbers of tourists who visit it.

Spanning more than 2000 km along the northeastern coast of Australia, the Great Barrier Reef is home to thousands of species of plants and animals. The Reef which runs parallel to the Queensland coast has been designated by the Australian Government as a Marine Park.
Few can imagine the biological diversity of the reef. One probably has to realize first that the 2000 km long reef runs predominantly in the North-South direction, therefore spanning a wide range of climates. Rain forests and mountains are predominant in the northern islands, while the southern islands are composed mainly of Coral Cay. Apart from its environmental value, the area offers visitors a variety of activities including scuba diving, snorkeling, water sports, and birdwatching.

Unfortunately for Capt. James Cook, the man who mapped the Pacific Ocean and claimed most of it for the British Empire, the Great Barrier Reef lies underwater -- where it has snared many ships since grounding Cook's Endeavour in 1770.

The world's longest-spanning natural wonder (not including auroras) is ironically the most fragile. The 2,000-kilometer (1,242-mile) reef, which sweeps along the northeast coast of Australia, is made up of the skeletons of generations of marine polyps that lived and died just under the surface of the crystal clear sea. Pollution, climate change and human intrusion are some of the factors endangering the delicate lime-based coral that covers some 344,000 square kilometers (137,600 square miles), often as close as 50 kilometers (31 miles) from shore. The reef -- home to the current generations of polyps -- is also inhabited by many colorful and exotic species of marine life. Nearly microscopic fish co-exist with much larger whale sharks, countless shellfish and other fanciful creatures.